Journal of
Languages and Culture

  • Abbreviation: J. Lang. Cult.
  • Language: English
  • ISSN: 2141-6540
  • DOI: 10.5897/JLC
  • Start Year: 2010
  • Published Articles: 120

Full Length Research Paper

Inflectional morphology in Mecha Oromo

Gobena Wakweya
  • Gobena Wakweya
  • College of Social Sciences and Humanities, Department of English Language and Literature, Jimma University, Ethiopia.
  • Google Scholar

  •  Received: 30 August 2016
  •  Accepted: 04 November 2016
  •  Published: 31 August 2017


This study provides relatively detailed descriptions of inflectional morphology in the Oromo language. It identifies occurrence patterns of morphemes and draws rules for inflections in the language. Although it focuses basically on inflectional morphology, it in some ways, deals with derivational processes and syntactic structures for comparison and relational analysis. A degree of fusion of morphs and morphological occurrences of inflectional formatives have been thoroughly dealt with. The thesis describes the inflectional forms of, essentially, nouns and verbs. However, words occurring in the nominals and verb-related words occurring in the predicate position have also been examined. Since the two word classes (nouns and verbs) are mostly the ones that undergo inflection, they determine the inflectional characteristics of the language. The study consists of five chapters which are concerned, respectively, with introduction in which preliminaries and methodology are treated, literature review which deals with some related concepts and previous works on Oromo, nominal inflection (including nouns, pronouns and adjectives), verb inflection (including verbs and adverbs) and conclusion. Number, singulative, gender and case are considered in the nominal inflection. Verb inflection is described in terms of inherent and agreement properties of grammatical function. In the descriptive chapters, distribution of morphemes and their allomorphs, along with their hosts, have been examined. This study provides a relatively more comprehensive and detailed description of inflectional morphology in Oromo, and hence the research outcomes are more focused to forms and functions of inflections.

Key words: Inflection, derivation, nominals, verbs, morphology.

Abbreviation: Brings, Changes to; *, ungrammatical; 1, first person; 2, second person; 3, third person; Abl, ablative; ABS, absilutive; Asso, associative; Aux, auxiliary; ABen, auto benefactive; Ben, beneficiary; CAUS, causative; Conv, converb; Cop, copula; Ep, epenthesis; Emph, emphasis; f, feminine; Foc, focus; Gen, genitive; Imp, imperative; Impf, imperfective; Ind, indefinite; Inf, infinitive; Inst, instrumental; Juss, jussive; Loc, locative; m, masculine; MD, middle voice; Mod, modality; Neg, negative; Nom, nominative; Ø, zero morpheme; Pas, passive; Perf, perfective; pl, plural; PRG, progressive; Ref, reflexive; sg, singular; Sing, singulative; VN, verbal noun.


Oromo is one of the languages of the Cushitic family in the Afro-Asiatic super family (phylum). It is called Afaan Oromoo by the speakers of the language. The present study uses ‘Oromo’ referring to both the language and the people as this is commonly used in the literature. Several varieties of Oromo are spoken in Ethiopia, Kenya and some parts of Somalia. In Ethiopia, Oromo is the largest ethnic group, and the language is spoken over a vast area of the country. According to the 2007 census of Ethiopian population, about 37% of the country’s population is speaker of Oromo. It is currently a medium of instruction at first and second cycles of elementary school level in Oromia regional state. At this level, all subjects are taught in Oromo. At the secondary and preparatory levels, Oromo is offered as a subject. It is also given as a field of study at the university level. Furthermore, Oromo is a language of mass media and administration in the  Oromia  regional  state  and  in  themass media at the federal level of the country, Ethiopia besides Amharic which is the major federal language.

Various studies have been conducted on the Oromo language since the nineteenth century. The research outcomes include grammars and descriptions of the various aspects of the language. The earliest works on Oromo deal with the grammar and lexicography of the language. Tutcheck (1844) and Viterbo (1887) are perhaps the earliest works on the Oromo grammar and lexicon. Onesimos Nasib translated the bible into Oromo using the Ethiopic syllabary at the end of the eighteenth century (1899) along with other short literary materials some of which were done with Aster Gano (cf. Mekuria 1995). Word formation was part of the works of grammar in both categories of inflection and derivation. Inflection signals grammatical relationships of lexical items in syntactic constructions but derivation results in new words.

Statement of the problem

Based on the way morphological strings are applied on stems in typological analysis, languages are classified into three major types: (1) isolating, (2) agglutinating, and (3) fusional. Isolating languages tend to have no morphology at all. An independent morpheme carries grammatical information. Agglutinating languages consist of a stem with one, or in some cases, more sequential affixes that can easily be separated. In such languages, morphemes and morphs are in one-to-one identifiable correspondence. Fusional languages often use a single form representing various morphemes that is a form indicating several functions. Contrary to what is observed in isolating and agglutinating languages, the fusional ones do not display one-to-one correspondence between morphs and morphemes. Some scholars make classification of morphological typology as analytic, synthetic and polysynthetic (incorporating). In analytic languages, grammatical categories are represented by independent morphs. In synthetic languages, morphs of grammatical information are attached to roots or stems concatinatively. Polysynthetic languages are similar to the synthetic ones except that in the former concatenated morphs in a word are many and the word is long. In view of the aforementioned explanation and previous works, I considered that Oromo is typologically a synthetic (fusional) language. Some scholars categorize word forms of languages as analytic, synthetic and polysynthetic. While analytic languages are simple isolating, synthetic and polysynthetic are inflecting, of course, the latter type being languages with long word-forms. Most languages of Semitic typology are nonlinear or of fusional type. For example, in Amharic /s-b-r/ is a root for ‘break’ which can result in different derived words by inserting various vowel patterns, that is, without sequential  morphs.  The   arrangement   structure   of   a word’s constituent units across languages is governed by morphological rules in the respective languages.

Morphology studies the word structure of a language derivationally and inflectionally. The latter is meant for the construction of sentences. Both the derivational and inflectional word forms are realized in a sentence though their structural analysis is done within words. As Aronoff and Fudeman (2011: 168) state “derivation gives you new lexemes, and inflection gives you the forms of a lexeme that are determined by syntactic environment”. Consequently, the derived word can change its placement in a sentence but the inflected form is made to occur in a specific position in a given syntactic context. Many grammar books which involve the treatment of derivation and inflection have been produced on the Oromo language. A separate and close examination of the latter seems to be lacking. Declension is the modification of nominals (nouns, adjectives, and pronouns) for grammatical functions, while conjugation is the change of the verb form to fit a syntactic context (Janda and Townsend, 2002). The motivation for this study was the absence of a comprehensive study on the inflectional morphology in the Oromo language. Thus, the study attempted to answer the following research questions in relation to Oromo.

(1) What is the structural distinction between root, stem, and inflected forms?

(2) What are the occurrence patterns of inflectional morphemes?

(3) What relational and/or differing forms are observed in inflectional occurrences distinct from derivational patterns?

(4) What are the characteristics of inflectional morphemes?

Objectives of the study

General objective

The general objective of this research is to describe and explain inflectional morphology in Oromo. The description focuses on the formal and functional characteristics of the inflectional morphemes in the language.

Specific objectives

This study aims to achieve the following specific objectives:

(a) To identify and classify inflectional morphemes.

(b) To classify inflectional phonemes and characterize the relationship between root, stem and inflected forms.

(c) To show the occurrence pattern of inflectional morphemes.

(d) To compare the pattern of inflectional morphemes with that of derivational morphemes.

(e) To identify the rule(s) of inflectional processes.


Data collection

Three research instruments were employed for data collection. The primary one was introspection, because I am a native speaker of Oromo, particularly, the western (Wallaga) variety. Corpus data and discussion with some natives were also intended to be sources of the necessary data. Involving few natives as informants is for confirmation purpose; discussing with them helped the data to be genuine enough. Two of my informants, Endashaw Jiru and Birhanu Diriba, reside in Addis Ababa, whereas the other one, whose name is Nasibu Gudina, lives in Nekempt whose visitation was in time gaps. The data collected were paradigms of word-forms and sentences with relevant patterns. Sentences are utilized for relational consideration as inflection is a morpho-syntactic feature.  Corpus data and discussion with other natives took place next to provision of the necessary data through introspection. The corpora was collected by reading texts and grammar books and also by recording short narratives written in Oromo.

Data analysis               

The data were used in phonemically transcribed version which is similar with the Oromo language’s orthography except some phonemes that are specific to the language. The orthography uses almost the same characters with the IPA alphabet. Words were analyzed into morphs and then glossed. The English equivalents were provided for the data used in the analysis. Morpheme(s) were examined for their forms and functions and described in their pattern of occurrence. After careful examination of the data, exemplary interpretation was provided in chapters three and four. Finally, based on the analysis and interpretation, conclusions were drawn.


Inflection of nominals
Word classes of nouns, pronouns and adjectives can be described under nominals. Nominals are inflected for various grammatical properties in Wallaga Oromo. The change of form of nominals for grammatical purposes is referred to declension. This section provides similarities and distinctions among declensions of the nouns, pronouns and adjectives along with the way they behave in inflection. In doing so, the forms of root, stem and word will be identified as well.
Noun inflection
Almost all nouns in Oromo end with a vowel except for a few of them which ends in specific consonants like n, l, t. Inflectional categories that are inherent to nouns exist in four major types. These are marking number, singulative, gender, and case. Number and gender are inherent categories, while case is relational because it is signaled in a sentence by the paradigmatic form in which it is used (Gragg, 1976: 182; Griefenow-Mewis 2001: 41). The singulative form is significant in Wallaga Oromo.  
Wallaga Oromo distinguishes between plural and singular nouns. Plural nouns are marked in different ways. Several types of suffixes can be attached to nouns to make plural forms. In collective nouns, some exist in plural form only (e.g. hamaamota‘bride servants’), whereas some others have the same singular and plural forms like ilkaan ‘tooth/teeth’. In some cases, the plural marker varies based on semantic nature of the noun. 
As shown in Table 1, the occurrence variation between -ota- and -oota- is based on the penultimate syllable of a base noun. When the penultimate syllable contains short vowel, -oota- is suffixed, but when it contains long vowel -ota- is suffixed for plurality of the nouns. These allomorphs occur in complementary distribution based on the phonological nature of the noun hosts that is the vowel length of penultimate syllables in the nouns. It occurs with ± animate nouns.   
Nouns of kinship terms are marked for plurality by the morpheme -an, which follows either geminate consonant or short /a/. The morpheme triggers the consonant to be geminated when it is appended. It may also occur by lengthening the final short /a/ on the base word when the base noun ends in short /a/ followed by gemination or consonant cluster (Table 2).
The morph –lee is suffixed to inanimate nouns that end in long vowel as in Table 3, whereas its allomorph -olii is suffixed to animate nouns with a long vowel in the preceding syllable and which end in short vowel. The plural marker -ilee is suffixed to inanimate nouns, whereas -olii is used with animate nouns. The allomorph –olee can be used with ± animate nouns. Both -olee and –ilee are suffixed to the nouns with long vowel in the penultimate syllable. 
Non-human nouns are marked for plurality by the morph –een suffixed to the noun roots. It is appended to two syllabic nouns that end in short /a/ sound. If the allomorph is preceded by glides and nasals, it makes the consonants to be geminate. 
The plural marker -an can be preceded by the geminate consonant -ww- when it is appended to nouns with long terminating vowels, but the nouns can be ± animate like the domains of the plural morpheme -(o)ota (Table 4).
As in Table 5, ± animate nouns may take the plural morph -an but the phonological form of the nouns, that they end in vowel length, makes the morph preceded by the geminate phoneme /-ww-/ for settling occurrence of impermissible number of vowels. The consonant is doubled   because the morph -an occurs followinggeminate consonant. + Abstract nouns are members of this morpheme which is preceded by the epenthetic element /-ww-/. All the suffixes in Table 5 are utilized for a noun ending in a vowel(s). 
Some nouns are used in the same form in singular  and plural paradigms. Syntactic context and relational consideration is peculiar proof for identifying status of such nouns in terms of their number (plural/singular). Nouns that name body parts are the same in their singular and plural forms. Plural forms of some nouns are apart from the ones indicated earlier; they seem to be irregular plural forms as in the third row of Table 6. Nouns which name things with the notion of generality like iǰoollee ‘children’ are used in plural form only. They do not have singular forms or the base forms cannot be stripe out of the inflected.Some nouns code between their singular and plural forms by the final syllables on their base forms; for example, waraabessa ‘hyena’ vs. waraabeyyii ‘hyenas’. Such forms seem to be contrastive in their final syllable -ssa and -yyii on the lexical item. In some cases, members of the different categories of plural markers can be possibly alternated for taking number marker; for instance, fard-een ‘horses’ or its alternate form fard-oota ‘horses’, kitaab-ilee ‘books’ or the alternate form kitaab-ota ‘books’ can be used. Different markers of plurality can be used together on a noun of kinship term; for example, fira ‘relative’ ®firoota ‘relatives’ /fir-oot(t)-an ‘relatives’. The ± animate nouns can be pluralized by different morphs based on the phonological form and choice of the base word. There are multiple of forms to make nouns plural, and these are appended to nouns on the basis of the language’s internal segmental and auto-segmental (gemination and vowel length) occurrence pattern as well as semantic type of the nouns.  
In Wallaga Oromo, a proper noun can be suffixed with the associative marker –faa to identify a group referring to human, that is, the morpheme -faa is suffixed to someone’s name in the group. It is mostly suffixed on interrogative pronoun eeňňu ‘who’ in questions.
The morpheme –faa can be appended to proper nouns and interrogative pronouns either in nominative case paradigm or in the object form as in Table 8. The nominative markers precede the associative marker as in the Table 7.
The singulative marker shows that noun is marked for being used as single form which may or may not be definite. This grammatical property is marked in Wallaga Oromo using -ičča (for masculine) and -ittii (for feminine). In some studies, these two markers have been considered to be definiteness markers (cf. Nordfeldt, 1947:26; Launhardt, 1973: 107; Gragg, 1976:181; Mohammed and Zaborski, 1990:10); while, Oromo does not have any overt marker of definiteness which means a specified noun that can be either singular or plural. However, the singulative marker entails definiteness being with singular nouns in Oromo. The morpheme –ičča in the inflected form in Table 8 is considered as the object/citation form which can be varied to -ičč-i whose final -i marks nominative case. Both the morphs -ičča and -ittii tend to be singulative markers embodying the property of definiteness. The following sentence provides an example for an indefinite singulative form: 
[2]   (a)  nam-ičča tokko    waam-ee-n ɗuf-e
man-Sing:ABS     one       call:1sg-Conv-1sgm       come:1sg-Perf
‘I came after calling a man’
In example [2] (a), -ičča shows an indefinite singulative property. Therefore, the basic functions of the morphemes (-ičča and -ittii) are marking the singulative property. Had they been definiteness markers, they could have possibly been used with plural nouns; but that is not permissible. The function of these morphemes as definite, however, can be understood on the basis of semantic aspect of the sentence.
Two types of  gender,  that  is,  masculine  and  feminine,  exist in Oromo (Gragg, 1976:180; Mohammed and Zaborski, 1990:5; Griefenow-Mewis, 2003:22). These are identified through gender marking suffixes, or lexically by using different words for masculine and feminine forms. The distinct words for masculine and feminine like adaadaa ‘aunt’ and eessuma ‘uncle’ are also used in Oromo. Gender indicating words can be used for animals and they are placed immediately after or before the nouns they belong to. The most common contrastive pair of words used in this way is kormaa ‘male (m.)’ vs. ɗaltuu‘ female (f.). Consider Table 9.
In Table 9, the first two examples are distinguished for gender lexically. The third and fourth nouns that are derived from verbs indicate that the long -aa suffixed to the verb root or to a C-final stem marks masculine gender, whereas the suffix -tuu makes verbal nouns in feminine gender. Lexically, gender coding nouns distinguish between masculine and feminine genders by their contrastive final syllables as -ssa vs. -ttii. Such nouns that are derived from adjectives indicating gender distinction. Proper nouns may also code gender distinction by varying their final vowel like Gaaddisaa (m.) vs. Gaaddisee (f.) in Oromo.
Some nouns may end in derivational morpheme -tuu, and they are used with no gender distinction (they are epicene). Even though they seem to end in the feminine form, the nouns are gender neutral. Each example below is either masculine or feminine:
[3]   (a) hat-tuu         ‘thief’
(b) kaɗat-tuu    ‘beggar’
In  [3]  (a)  and  (b),  the  roots  are  verbs.  They  becomenouns by the suffix -tuu. In Wallaga Oromo, non-human nouns, as the example [4], are syntactically used as feminine.
[4]   (a) aduu ‘sun (f.)
(b) daččee   ‘land (f.)’
Example [4] (a) and (b) shows that non-human nouns are considered as only feminine gender in Oromo. Such nouns can be used with feminine gender marker -ittii; however, its function is either feminine or diminutive marking. For example, saree ‘dog’ ®sar-ittii ‘dog-f’. The noun saree ‘dog’ is considered feminine gender or diminutive form so that they normally take the marker of singulative property in the feminine form (Baye, 1981: 18).
The relational category, case, is a grammatical relationship of nouns or pronouns to other words in a sentence. Faarlund (2004: 16) defines case as a morphosyntactic category which is construed in its syntagmatic occurrence. Languages differ especially in morphological case rather than syntactic case. “Syntactic Case is universal, while morphological case is language-specific” (Mcfadden, 2004: 3). Wallaga Oromo marks nouns for case. According to Nordfeldt (1947: 22), there are six types of cases in Oromo: nominative, accusative, genitive, dative, ablative and vocative ones; he considers the absolutive case as the primitive form of nouns. Several cases exist in Oromo encompassing syntactic and semantic bases of case assignment with distinct inflectional markers for each. These include: nominative, absolutive, genitive, dative, ablative, instrumental, beneficiary, vocative, locative cases. They show their semantic roles on the basis of syntactic relational structures.
In Wallaga Oromo,  nouns  that  are  used  as  subject  of intransitive verbs and agent of the transitive verbs take the inflectional morpheme for the nominative case. The nominative case is marked by four different morphs of allomorphic variation occurring in complementary distribution. The allomorphs for the nominative case are -n,-ni,-i and Ø.
The difference in the phonological realization of the nominative case markers arises from the phonological nature of the nouns. The marker -n occurs after a terminating long vowel of a noun, including the derived nouns. For a noun base that ends in short vowel, the final vowel is dropped and -ni is suffixed to mark nominative case. It makes either gemination or consonant cluster. The allomorph -i is appended to noun roots or -C1C1 and -C1C2 final stems. Nominative case can also be marked by zero morph when the noun ends in consonant as in the last noun in Table 10; the case is understood by considering placement of the noun and the syntactic function it conveys.
Some consider the unit –ti as a separate nominative case marker (Launhardt, 1973: 40; Griefenow-Mewis, 2003: 42). The morpheme -ti is used as an optional extension of genitive case marker as in mana namaa-ti‘ house of man’ as it occurs after the genitive marker, vowel length (Gragg, 1976: 183). It is a copula in a possessive construction (Ishetu, 1981: 12). It can also be used as a phonological variant of the morpheme -ni in nominative case. The nominative case allomorph –ni undergoes phonological processes and gets changed to -ti, for example, bofa ‘snake ABS’ - bof-ni ‘snake Nom’ - bof-ti ‘snake Nom’ in which -ti results from partial assimilation process in the shares vocal feature between the segments /f/ and /t/. In some Oromo dialects it is pronounced as bofni without undergoing the phonological process. When the focus marker -tuis suffixed to a noun in the subject position, no case marker is used. Debela and Ronny (2003: 165) and Baye (1988: 371) state that the morpheme -tu is a contrastive focus marker of nominal. Baye (1988) indicates that this contrastive focus phenomenon is construed in context because it contrasts the focused nominal with other presupposed constituents providing context.
[5]   nam-ičča-tu       na    waam-e
man-Sing-Foc   me    call-Perf 
‘It is the man who called me’
Example [5] illustrates that the nominative case  marker
tu marks a focused subject in the contrastive context of the others.
The base form of noun is the unmarked one, the so called absolutive case in Oromo, it is an underlying noun that occurs in the object position without an inflectional suffix. In addition, we will be having all the final vowels with their long forms as markers of object paradigm if we consider Oromo as an object marked language. It usually ends in vowel(s) which Gragg (1976: 194) states as ‘stem-formatives’. Owens (1985: 18) defines the absolutive case as the citation form used in the object paradigm. These forms are considered as inherent stems used in the position of direct object. Oromo is a marked-nominative language in which the object is unmarked. Inherent noun like kitaaba ‘book’ is treated in the absolutive case.
Consonant ending nouns occur with the suffix –n in the object position. Sometimes an object seems to be marked; for example, Galaanii(n) ‘Galaan-(Emph)’. According to this example, in consonant ending nouns, it seems that the morpheme -n can be appended to citation form in the same way as pronouns; for example, isaanii-n ‘them-Emph’. Perhaps, the suffix -n is a focus marker on object since the language is object unmarked in terms of case. Pronouns and demonstratives seem to be distinguishing between subject and object forms as in is-ni ‘he-Nom’ vs. is-a ‘he-Acc’; however, this form is not compatible for all pronouns as well as nouns. It calls for more explanation.
Wallaga Oromo marks an indirect object known as dative case, which is also called oblique case. Dative case signals a noun that takes the position before or after the direct object with the function of telling ‘for whom’ or ‘to whom’ the action is done as semantic criteria. Two different markers can be suffixed to nouns in order to mark the dative case. Dative case uses-f as commonly occurring suffix in this case (Owens, 1985: 105). Consider the examples in Table 11.
The dative case markers are the two underlying morphs of inflectional suffixes which are -f and -tti. These morphs are distinctly used in Wallaga Oromo; their basic functional difference falls between the morph -tti, which is basically adpositional form (Owens, 1985: 112), signals goal or addressee whereas the suffix –f shows addressee with a sense of beneficiary in dative case. Another difference is that -f occurs after long vowel, but -tti can be appended to any noun in the same function (Table 11). Vowel length is used as a surface form in the same function on which the suffix -f is realized in the underlying form. The morpheme -tti occurs as in  muč’aa-tti  ‘to  boy’, making the same construction with dative forms in semantic consideration. The suffix -tti makes the sentence semantically distinct from the other marker (-f) in the dative case. For example, k’aršičča isa-tti kenni ‘give the money to him’. In this sentence, the money is supposed to be staying with ‘him’ for a short period of time. However, in the sentence k’aršičča isaa-f kenni ‘Give him the money’, indicates that the money will be possessed by ‘him’. Therefore, occurrence of –tti and -f may signal semantic difference in Oromo. According to Griefenow-Mewis (2003: 45), the dative case markers mentioned earlier (-f and -tti) are not the only ones used in Wallaga Oromo. It considers several markers inclusive of these suffixes. The dative case is marked by -f and -tti as the underlying inflectional forms which means they are the formal occurrences of inflection in our competence. However, when -f is appended to nouns that end in short vowel, the vowel needs to be lengthened being triggered by the suffix, because it behaves to occur after long terminating vowel. In the surface form, which is the uttered form, vowel length only seems to be a dative case marker, but it is only occurring in performance for utterance that it is not one of the allomorphs of the dative case; underlyingly, there exists the suffix -f. Nouns that seem to end in consonants can also be suffixed by the dative case marker -f after vowel length. Such nouns can be followed by a high front vowel -i as a copula, so that the case is marked by adding the suffix -f following vowel length. Even though the noun loon ends in consonant as in Table 11, the underlying dative case form is done in the same way with that of nama+f which becomes namaa+f. It will be loon(i)+f which becomes loonii+f. The long vowel without the final -f can be said; for example, ani loonii okaa haame ‘I cut grass for cattle’. In this sentence the noun loonii ‘for cattle’ is in the dative case paradigm whose underlying form is loonii-f ‘for cattle’.
The case marked on nominals for indication of possession is known as genitive case. Of course, genitive case is broader than possession inclusive of purpose, source, reference, etc. The marker of genitive case in Wallaga Oromo nouns is vowel length, which is lengthening a short ending vowel of a noun. According to Ishetu (1981:13), genitive case is formed in two ways: by prefixing kan and lengthening the last vowel (or suffixing -i to final consonant of the possessor noun; and by juxtaposing the thing possessed and the possessor in that   order   and   lengthening   the   final   vowel   of   the possessor if it is short (or suffixing -i after -C). However, all about genitive is the vowel length only on the possessor noun. In possession, if the vowel of the noun possessor is already long, occurrence of the possessed noun just before the noun possessor signals the genitive case. Using kan before the possessor and lengthening the short terminating vowel is also the other way of constructing genitive forms in syntactic form. It does not make gender distinction in Wallaga Oromo; however, in some other varieties like Hararghe, varying the initial letter to /t/ makes gender difference. Thus, tan is used referring to feminine gender. Table 12 may clarify the point more.
Vowel length is the marker of genitive case on a noun as in shown in Table 12. The vowel length on the genitive noun occurs by the position of the possessed noun right before. If the noun ends in short vowel, it is lengthened. When the noun base ends in long vowel, positioning the possessed noun right before the noun possessor indicates genitive case as a phrasal form like uffata muč’aa ‘clothes of baby’. 
The use of instruments or a means of doing something is termed as the instrumental case (Table 13). In Wallaga Oromo, it is marked by -n. The instrumental case marker is utilized based on the spelling of the nouns in almost similar way with that of the dative case as discoursed so far.
As is clear from the examples, the instrumental case marker is –n which occurs following long vowel. For a noun that ends in short vowel, the ending vowel is lengthened to append a marker of instrumental case. Nouns ending in consonant are followed by the copular vowel -i which is lengthened before suffixing the instrumental case marker –n in the same way with that of the preceding example. Other elements especially copulas can be suffixed to nouns preceding the instrumental case marker indicating cleft system in semantics as in the following example sentence.
[6]   kop’ee      namaa-tii-n                  deem-i
      shoe          man:Gen-Cop-Inst       go-2sg:Imp
‘Go in someone’s shoe’ 
Copulas are placed before instrumental case marker –n to indicate the instrumental from in cleft system, but they are not applicable for the nouns that end in short vowel; for instance, *harka-ɗaa-n ‘hand-Cop-Inst’. They precede -n when the terminating vowel of the noun is long vowel and the case is instrumental, for example, Ɂeboo-n ‘Spear-Nom’ or Ɂeeboo-ɗaa-n ‘spear-Cop-Inst’. Its sense shows that the copulas make the instrumental case easily understandable fulfilling that the suffix -n follows lengthened vowel rather than the already  long  vowel.  In the cleft system, Ɂeeboo-ɗaa-n “spear-Cop-Inst’ is to mean kan fajjadame Ɂeeboo-ɗa ‘what he used is spear’. However, this thesis focuses on the overt morphology only that it does not enter into the details of the cleft system. Instrumental case is marked on the adjectives or demonstratives if any. When a noun is modified by an adjective, it is the adjective that is marked for the instrumental case. An exceptional usage of instrumental case in Wallaga Oromo occurs when the marker is seen on the verb just as on the noun; for example, deem-ii-n   go-2sg:Imp-Inst   ‘use it to go’. This example is the verb inflection for case. Such form can also mean take this horse away in addition to the indicated meaning and function.
The source, origin or from where a movement begins is expressed by the ablative case which is marked by vowel length in Wallaga Oromo. For nouns that end in long vowel, long -aa and -ii following copular elements -ɗa and-ti respectively are used to show ablative case. Table 14 provides the examples.
Vowel length is about lengthening of a short vowel, especially, referring to long -aa and -ii to mark ablative case. Nouns that end in long vowels are marked for ablative case by placing copulas -ɗa or its allomorph -ti before the lengthened final vowel of the case. The interesting point is that such form distinguishes ablative case from the object form of nouns in its morphology. For example, *Adaamaa ɗuf-Ø-e ‘He came to Adama’. In this sentence, the noun Adaamaa ‘Adama’ is the absolutive noun which may indicate locative or object or else ablative, but when it becomes Adaamaa-ɗaa ɗuf-Ø-e ‘He came from Adama’, the noun form Adaamaaɗaa ‘Adama:Abl’ is clear to be in the ablative form.
Locative case is marked by the suffix -tti, and tells location for some occurrence, goal or addressee. This case seems to be antonym to the ablative case in that it is “to” whereas the ablative case “from” is in the opposite direction. Owens (1985: 110ff) states -tti as locative case in addition to that it considers the morpheme (-tti) as suffix appended to human noun indicating goal as postposition.
Locative case as shown in Table 15 indicates location. It may also indicate goal or addressee as in aangoo-tti ‘authority-Loc’ which shows addressee, but it may indicate goal when appended to human as in nama-tti ‘to man’.
In Wallaga Oromo, gaining from the result of something ismarked on nouns by a suffix –f that follows long vowel, and called beneficiary or benefactive case. Beneficiary is used referring to gaining from result of some happening whereas benefactive case marks for benefitting from something. In this paper, such marking is indicated by beneficiary.  
The paradigmatic forms indicate that the beneficiary marker -f after long final vowel on a  noun  point  out  that there are gains from something. Since the same markeris appended for dative case, the verb type and semantic aspect determines beneficiary. The noun in the beneficiary occurs with intransitive verbs. Such constructions are widely used in Wallaga Oromo.
Although case marker and morphological form of dative and beneficiary seem the identical, the verb type with its arguments determines the case type (Tables 16 and 17). If the verb is constructed with direct and oblique objects, the oblique one is in the dative form whereas when the verb is intransitive or linking verb for the benefit of someone, the noun form is in the beneficiary case by using monovalent or bivalent verbs. Number of arguments and semantic features need to be considered for the distinction between dative and beneficiary cases.   
Some languages have vocative case which marks the noun representing the entity (animate) we address. It is a verbal means of calling attention. In Wallaga Oromo, there are various ways of marking the vocative case. One is using the word ‘yaa’ referring to the addressee which is syntactic form.
The suffix -na which marks vocative case is appended to a noun which is two syllabic and ending in short vowel with harmonic occurrence of vowels (Table 18). Its full word form nana is used after nouns that end in long vowel; for example, gurbaa nana ‘you boy!’ It seems that the suffix -na occurs in allomorphic variant of its full word form nana as vocative case marker.  Sometimes the suffix -na can be used representing the word kana ‘this’; for example, bara-na ‘this year’. It can be identified based on the syntagmatic occurrence of the nouns with such particle. The marker of vocative case with incorporation of strong feeling -na or its full word form nana can never be used with proper nouns.
Another declensional class in the nominals, which is inflected for a number of categories, is pronoun. Inflection of pronouns is complex because it is less regularly patterned than noun inflection. That is it contains several suppletive forms of inflection phonological forms in their functional variation. Pronouns are inflected for properties of number, gender, singulative and case like the noun inflection. Launhardt (1973) describes some forms of pronoun inflection in the attempt to provide how to learn the Oromo language.
Personal pronoun
Personal pronouns  in  Wallaga  Oromo  appear  complex forms of inflectional indications. They distinguish their inflectional forms through their internal phonological forms or by suppletive forms in which complete replacement of the word indicates inflection in the language. The absolutive form of pronoun is the base form in the same way with noun that is the object form. It also distinguishes between masculine and feminine gender. Regarding the core case distinction in pronouns, the nominative case is marked in the same way with nouns applying the four allomorphs. The first person plural nu ‘us’ in the object form is marked for nominative case by the allomorph -i as nu-i ® nu-t-i ‘we’ (Table 19). The impermissible occurrence of V1V2 in Oromo is settled by the epenthetic consonant -t- which in other dialects is -j- becoming nu-j-i ‘we’. Second person singular si ‘you’ does not have a clear root; it seems to be diacronically metathetic element from the root is- ‘pronoun notion’, because this root is applicable for all pronouns, except first persons (calls for more study). The nominative form of si ‘you’ is ati ‘you:Nom’ by suppletive form through complete replacement for grammatical function, so that it is not analyzed into *at-i ‘You-Nom’ because its whole is inflected form. Although the object pronouns are from the meaningless roots /n-/ and /is-/, they are considered absolutive because there is no specific marker of object form.
In the pronouns 3sgm and 3sgf, isa ‘him’ and ise ‘her’, the final vowels show gender distinction. Vowel -a sound is associated to masculine, whereas the vowel -e sound is related with feminine gender as in Nagaasa ‘masculine’ vs. Nagaase ‘feminine’. Therefore, they are like gender coding base forms of pronouns. In the 3sgf form, ise®išee undergoes phonological process of palatalization by movement of tongue s ®š /-high-mid front vowel. Second person plural pronoun isin and third person plural pronoun isaan are also used as honorific words referring to a single person. The citation or object forms are considered as the base forms of pronouns. Haymanot (1984: 8) distinguishes forms of 2pl pronoun isin and isini as object and subject forms, respectively showing the same form for 3pl isaan and isaani. However, consonant ending nominals are marked for nominative case by zero morpheme. The optional -i suffixed to nominals is for copular costruction as kun isaan-i ‘these them-Cop’. The controversial issue of marking pronouns in Oromo for accusative case is considered by several studies. Haimanot (1984: 19) used object pronouns in accusative case forms by the morpheme -n without describing their phonological distinction in advance; Debela and Meyer (2003: 174) marks pronouns of accusative case by -Vn. It puts two paradigms of object forms of pronouns as the base forms and the marked accusative forms.  The view of this is contrary with the works of the aforementioned studies, in this regard, that the issue of accusative case is never raised in this work.  It  has  been indicated that Oromo is an absolutive language in which object is not marked for accusative case by particular morpheme(s) (Table 20). The base (citation) forms of the pronouns are absolutively the onject forms that we do not have object markers. Next, the marked form is incompatible for 3sg pronouns that they have to remain in their base forms. The other, the morpheme -Vn will be -VVn for the C-final nouns. Therefore, the discourse related marked forms of the object pronouns can be seen in Table 21.  
Pronouns in object forms are marked by the morpheme -n which triggers the preceding vowel to be lengthened if it is short. Several morphemes behave like occurring after vowel length only. The marked object forms of pronouns are functionally for showing emphasis; not accusative case as we already have the absolutive case in object forms. These forms are situation based that they are understood more in discourse. For example, Inni isaanii-n waam-Ø-e he-Nom them-Emph call-3sgm-Perf ‘he called them’ has the meaning ‘it is them whom he called’ in relation with other participants of the discourse. The equivalent forms for 3sg pronouns seem to be suffixing the copula -ɗa for emphasis as isa-ɗa ‘him-Emph’ and išee-ɗa ‘her-Emph’. 
The nominative and objective forms of the pronouns can be seen in Table 21. Pronouns are inflected for several types of cases. The dative case is marked by -f and -tti. However, in some cases pronouns in the oblique case remain in the object form as in gaaffii si gaafate ‘he asked you a question’; no any marker. The base form of a pronoun functions as dative case.
[7]    is-ni[inni]        bišaan         sii-f[sii]       kenn-Ø-e
he:Nom             water         you-Dat          give-3sgm-Perf
‘He gave you water’                        
Example  [7]  uses –f to   indicate  dative   case   whereby vowel length can also be used as its surface form. The morph -tti can also mark dative case as in išee-n ergaa na-tti him-t-e, ‘she told me a message’ on the basis of meaning though in other contexts it can function as adposition. For example, saree-n na-tti fig-Ø-e ‘A dog ran to me’ in which –tti is an adposition showing goal to mean towards.
Double usage of dative case pronouns is permissible in Wallaga Oromo. The pronoun which is placed before the direct object shows focus on the indirect object, and is suffixed by-f whereas the second one appears in vowel length only whose underlying form is the same. The examples below illustrate more:
[8] (a) is-ni   anaa-f  baɗaasa naa-f[naa]     kenn-Ø-e
he-Nom    me-Dat  award  me:1sg-Ben  give-3sgm-Perf
‘He gave me an award’
(b) in-ni      išee-f     kop’ee      bit-Ø-ee-fii
he-Nom   her-Dat   shoe        buy-3sgm-Conv-Ben
‘He bought her shoes’ 
As in example [8] (a), the first person pronouns can be used in double form. It seems that when the dative pronouns occur before the direct object, the pronoun is suffixed by -f and it conveys focus. However, the pronoun of the dative case which is placed after the direct object uttered in vowel length only whose underlying form is with the suffix -f. Sentence [8] (b) indicates that third person pronouns do not allow the double appearance of the dative pronouns because on the final position of the sentence, -fii is suffixed to the verb following a lengthened vowel whose function is similar with the doubled pronouns in other pronouns. 
Personal pronouns are also inflected for ablative case. The adpositional particle –irraa marks ablative case on pronouns.
The ablative forms of pronouns indicating source is made by using the adposition -irraa because this adposition has got the meaning ‘from’ in its long final vowel (Table 22). It seems that this is the only marker of ablative case on pronouns.
Wallaga Oromo distinguishes between possessive adjectives and possessive pronouns. Possessive adjectives are used with nouns being encliticized where as possessive pronouns are used alone in sentences, and thus they are syntactic forms. The particle kan is prefixed to the possessive adjectives to form possessive pronouns that can stand alone in a sentence to indicate possession as in kankoo ‘mine’. Such forms are usually constructed with the copulas ɗa or -ti. The obligatory difference in the usage of the copulas is that the first and second person plural possessive pronouns kankeeňňa ‘ours’ and kankeessan ‘yours’ are used with the copula ɗa only. The copular element -ti can be used with the other possessive pronouns ending in long vowel; but ɗa can be used replacing -ti for the purpose of focus on the possession.
Reflexive and intensive pronouns
Both reflexive and intensive pronouns are differently used in Oromo. According to Launhardt (1973: 234), both the markers of(i)- ‘self (reflexive)’ and mataa ‘self (intensive)’ are for reflexive pronouns; however, from syntactic constructions we can understand that the former is for reflexive whereas the latter makes intensive pronouns (Table 23).
Reflexive pronouns
Reflexive pronouns show that an action refers back to the subject. They are formed by prefixing the particle of(i)-on possessive adjective forms of pronouns. A reflexive pronoun may come either right after its antecedent or after some words in a sentence and it remains reflexive regardless of changing its syntactic placement. Launhardt (1973: 233) indicates that subject and object cases are similarly unmarked.
Reflexive pronouns are inflected for several cases like nominative case as in ofiisaanii iǰaarani ‘themselves built it’ and dative case as in ofiikee-f ‘yourself-Dat’. Dative case is marked by –f on the reflexive pronouns (Table 23).   
Intensive pronouns
Intensive pronouns are formed in different ways from that of the reflexive ones. The intensive form mataa is procliticized to the possessive adjective form and it is syntactic aspect. Nominative case markers are suffixed to the word mataa preceding the possessive adjectives occurring with the intensive marker because it is usually placed right after its antecedent. Pronouns of this category are inflected for subject, object, dative cases and beneficiary.  
Intensive pronouns emphasize the subject. The nominative case marker –n is suffixed to the intensive pronoun mataa ‘self (intensive)’ in the subject paradigm (Table 24). The intensive pronouns come right after the nominative  nouns or  pronouns  to  indicate  intensity  or emphasis. The object forms of intensive pronouns occur in the absolutive form. Intensive pronoun occurs in the dative case being suffixed by the marker -f on the intensive pronoun. In both object forms and dative cases the intensive pronouns occur right after the object or citation forms of pronouns or after corresponding nouns.  
Intensive pronouns are used in subject or object positions following their antecedent nouns or pronouns; hence, they are inflected for nominative case. They are also inflected for dative case by the marker -f suffixed to the intensive pronoun.
[9] Dabaloo-n   ana     mataa koo-f    t’alayaa    erg-ee                    ǰir-a[erg-ee-ra]     
Dabaloo-Nom me    self   my-Dat  letter     send:3sgm-Conv   Aux-Impf
‘Dabalo sent me a letter’
When an intensive pronoun is used as a dative case, the direct object noun or pronoun is followed by intensive pronoun. The intensive pronoun is inflected for the case, whereas the pronoun in the direct object form remains in its base form as in example [8].
Demonstrative and interrogative pronouns
Demonstratives and interrogative pronouns have case as their common inflectional category, though the latter is marked for more number of cases than the former in Wallaga Oromo. Demonstrative adjectives occur after nouns to modify the noun (antecedent), whereas demonstrative pronouns are used alone in a sentence either in subject or object positions. Interrogative pronouns are marked for nominative, genitive and dative cases.
Inflection of demonstrative adjectives and pronouns distinguishes between nominative and absolutive forms. When demonstratives are used with nouns as adjectives as in man-ni kun-i ‘this house’, they are marked for nominative case following the nouns they are modifying. Demonstrative pronouns are also marked for nominative case as in kun-i mana ‘this is a house’.
The distinction between the absolutive and nominative forms is not the final vowel change, but the internal vowel /u/ makes the inflectional form in the use of ablaut in which vowel change shows inflection (Table 25). Occurrence if -i at the end in the nominative case as kuni ‘this:Nom’ and suni ‘that:Nom’ is dialectal variation. 
Even though these are basically pronouns, they can be used as adjectives modifying nouns. The plural form kanneen ‘these’ points to near things in object form. However, it is also possible to opt with the singular demonstrative pronouns kana ‘this’ for plural antecedents in Wallaga Oromo.
[10]   nam-oota       kanneen      waam-i
man-pl:ABS      these           call:2sg-Imp
‘call these persons’                                  
As in example [10], demonstrative adjective or pronoun can be used in plural form, but its singular correspondent can also occur without meaning change as in ǰabb-oota kana fuuɗ-ii deem-i ‘Take these calves away’. The singular form kana ‘this’ can also be used along with plural forms.
Interrogative pronouns
Interrogative pronouns undergo inflection for different grammatical properties. They are marked for number distinguishing between plural and singular (Table 26). In addition, they are marked for cases as subject, object, genitive and dative forms. Launhardt (1973: 246) states that –tu suffixed to the object form in order to mark focus in the nominative case. 
Nominative forms of interrogative pronoun are used in focused forms by the morpheme -tu which is a nominal focus marker. It indicates focused subjects used in the nominative case. Both dative and beneficiary cases are formed in the same morphology that they both are marked by the morpheme -f. The distinction between them is syntactic and semantic. The genitive case marker, vowel length, can be used with interrogative pronouns as in Table 26. Interrogative pronoun eeňňu is marked by -n in the object form. The morpheme is basically functional for showing emphasis but it occurs with the interrogative pronoun embodying the sense of objective indication.  
[11] eeňňuu-n     waam-t-e?
who-Emph         call-2sg-Perf
‘Whom did you call?’
Example [11] shows that interrogative pronoun occurs in object form being suffixed by -n whose function is marking an emphatic object.
Indefinite and reciprocal pronouns
Indefinite pronouns
Several indefinite pronouns are available in Wallaga Oromo and they undergo inflection. They are marked for number and case. The case indicated by indefinite pronouns between nominative and absolutive cases is rather syntactic because it is not morphologically distinctly marked. Indefinite pronouns can be marked for genitive and dative cases also. Launhardt (1973: 247) classifies indefinite pronouns into three based on their usage. According to him, there are indefinite pronouns referring to person only, those referring to animals and things only, and those referring to persons, animals and things. Indefinite pronouns are marked for few inflectional categories. The morpheme -llee, which means ‘ever’, gives the property of indefiniteness to pronouns when it is appended to them (Table 27). These indefinite pronouns are mostly used in negative constructions especially in jussive and imperative forms. The indefinite pronouns make contrastive relation between nominative and absolutive  cases  in   syntactic  forms   though  they   are morphologically the same. Here is an example sentence: 
[12] (a) namuu daree  hin  ǰeek’-n-e
man:Nom        class       Neg      disturb-Neg-Perf
‘Nobody disturbed the class’
In example [12] (a), the indefinite pronoun is in the nominative case though it can also be used in the object position. The suffix -uu makes indefinite pronouns when they are suffixed to the lexical item nam- which basically serves as a noun root when considered alone. It adds the property of indefiniteness as the stem namuu ‘nobody’. 
Reciprocal pronouns     
In Wallaga Oromo, reciprocity is expressed by wal(i) ‘each other’. This particle is inflected for dative, beneficiary cases as follows. The base form wal is as an object object.


The inflectional categories or properties of adjectives are the same with that of nouns. Adjectives are inflected for number, gender, singulative and case like nouns; however, sometimes they are marked differently from nouns. For instance, adjectives, unlike nouns, are inflected by reduplication to mark plurality.When adjectives occur with nouns in sentences, number is marked on both of them. Nouns are marked for plurality (cf. section 4.1.1), but adjectives are marked for number by reduplication of its initial syllable (CV, CVC), or by the plural suffix -(o)ota. In the former way of marking plurality, the initial syllable reduplication co-occurs with the final vowel shift from -aa to –oo when the adjectives end in long -aa. The latter way of marking number in adjectives is the same with that of nouns. According to Baye (1981: 29) and Launhardt (1973: 313), the suffix -(o)ota shows plurality in adjectives. Table 29 shows the different ways of marking plural adjectives with examples.
The lexically coded adjectives distinguish between singular and plural forms by their contrastive final syllables -ssa and -ttii. The plural number is also marked by reduplication whereby the final vowel shifts from long -aa to -oo occurs for most adjectives of such form.
Reduplication of the initial CV or CVC syllable can be a marker of plural number. This occurs on adjectives that are formed from other part of speech and on the compound adjectives like harka-k’alɁeessa ‘poor:sg’ ®harka-k’alɁeeyyii ‘poor:pl’. The third row of Table 29 shows that the suffix -(o)ota is also a marker of plurality on adjectives.
In Oromo, the base forms of adjectives are normal to be used with masculine as in gurraačča ‘black:m.’, that is, they are basically masculine related. Inflection occurs when we make them fit for the feminine as gurraattii ‘black:f.’. Variation of the final syllables on these adjectives is lexical form seemingly suffixal forms of feminine gender –ittii and -ičča of masculine. This is for adjectives that can also be used as nouns. Adjectives that are invariable between gender distinctions also exist in Oromo. Table 30 shows some examples of Marked Gender on Adjectives.
For many adjectives that end in long -aa, the morpheme –tuu is suffixed dropping the long vowel -aa so that it marks feminine gender. However, some adjectives ending in long -aa can be marked by shifting the final -aa to -oo. Some adjectives like garraamii ‘kind’ happen with no inflection to mark gender that means the same form is used for both masculine and feminine. There are adjectives indicating gender to distinguish between masculine and feminine (Mohammed and Zaborski, 1990). They are used after the noun they refer to. For example, saree kormaa vs. saree ɗaltuu can be considered in which then adjectives kormaa and ɗaltuu are gender distinguishers coming after those nouns. Markers of singulative property –ičča (for masculine) and -ittii (for feminine) occur on adjectives also as for nouns. Singulative markers are not used on both a noun and adjective at the same time. When noun is marked, adjective is not and the vice versa.
 [14] (a) muk-ni[muk-ti]ɗeer-ičč-i           
stick-Nom                 long-Sing-Nom 
‘The long stick’
(b) muk-ičč-i       ɗeeraa-n                                                                                          
stick-Sing-Nom    ling-Nom 
‘The long stick ’
Singulative markers occur on either an adjective or a noun when they are used together as in examples [14] (a) and (b). Adjectives are marked for singulative especially when they occur after the relative pronouns inni and išeen as in (a). Marking singulative property on both noun and adjective is ungrammatical *muk-ičč-i ɗeer-ičč-i ‘the long stick’ because the singulative marker is appended on both the adjective and noun.
If a noun is marked for nominative case, an adjective following it will also be marked for the same case. Table 31 clarifies the point. The phrases in Table 31 exemplify that adjectives following a nominative noun are marked for nominative case whether the adjective is occurring either in suffixation or reduplication. The same rules (markers) of nouns apply for the adjectives for nominative case. 
As indicated in Table 32, the nominative case is marked by four allomorphs whereas the absolutive case is the unmarked object form. Dative case is marked by the underlying suffixes -f. Genitive case is marked by vowel length on the noun or pronoun possessor. The instrumental and beneficiary cases are marked by -n and -f respectively. These are suffixed to the nouns or pronouns under the case.  
Inflections of verbs
Verbs are the most significant class in undergoing several inherent and agreement inflection and thus complexity of conjugational occurrences is noticeable. As Katamba (1993: 220) indicates,  “in  most  languages  the
verb shows greater morphological complexity than any other word class”.
Verbs and inflection
In the Oromo language, the base stems of verbs are the infinitive (verbal noun) forms ending with morpheme -uu as in mur-uu cut-VN ‘to cut/cutting’. We can classify the verbs in Oromo into three types as action/stative, auxiliary and copula. The action verbs can be used in different derivational forms like causative and passive constructions. Auxiliary verbs, which occur as helping verbs, can be considered as action/main verbs when they are used in the absence of another action verb in a sentence. They are basically functioning as helping verbs being with other action verbs in a sentence. The invariable particles functioning as copula do exist in the language. They are ɗa and its negative form miti, but the positive copula ɗa can be varied to -ti, which usually occurs in genitive construction or -i, which occurs with nouns or pronouns ending in consonant.
Verb inflection happens for inherent and agreement properties. Inherent properties are the basic members of a word class triggering inflection on that word class whereas agreement properties indicate inflection of a word class for properties out of its members (cf. section 2.4). Besides inflection of their inherent properties, verbs are inflected for agreement purposes based on forms of their root or stems. We can identify two types of verbs according to the root forms and their agreement properties. The majority of verbs are conjugated in a regular manner to occur in agreement with subject as Oromo refers to a subject agreement inflection on verbs. The other rare verbs whose root ends in consonants /Ɂ/, /h/, /ɗ/, /j/ and whose inflected forms happen in special ways with their vowel change seem to be irregular verbs. The conjugational pattern of the regular and irregular verbs can be shown as in Table 33. 
In Table 33 conjugation of the verb root raf-, the perfective marker -e which is varied to -i used with second and third person plural pronouns. The morpheme -t- marks person on verbs as an agreement suffix. However, in other context, it marks person and gender as a cumulative morpheme. Therefore, the morpheme can be considered as an agreement marker of person and gender on verbs. Here, are examples:
 [15] (a) an-i         raf-Ø-e
I-Nom     sleep-1sg-Perf
‘I slept’                                
(b) at-i               raf-t-e
you-Nom     sleep-2sg-Perf
 ‘You slept’
In example [15] (b), the morpheme -t- marks second person singular pronoun in contrast with its unmarked (zero morphemic) correspondent on first person singular as in example [15] (a). It also conveys a feminine gender when the verb is used with the third person singular pronoun as is seen in Table 34. Haimanot (1984: 11) indicates that the morph -t- is a person agreement marker for second singular and plural, third singular feminine types   of   pronouns;   the   rest   are  marked    by    zero morphemes. However, the agreement marker -n- seems to be a cumulative morpheme conveying person and number functions in first and third plural pronouns. Example, raf-n-e ‘We slept’ in which the suffix -n- agrees with the first person and plural pronoun.  In general, the suffix -t- marks the verb to distinguish between genders or persons which are contextually identified. Negative forms of the verb conjugation in Table 33 above are done by using the negative proclitic hin- and the dependent suffix -n- after the verb. For instance, hinraf-n-e Neg sleep-Neg-Perf’ is the negative form for all the varied forms in the table. In negative perfective aspect, the verb form is uniform across the paradigm. No agreement marker is used. The perfective marker is similarly -e which follows the dependent negative suffix -n-. In imperfective forms, the suffix -u can be considered as the dependent negative marker along with the proclitic hin except for second and third person plural pronouns whose marker is -an instead. These are also the markers of imperfective aspect.  
Transitive and intransitive verbs whose roots end in the glottal phonemes /Ɂ/, /h/, the implosive /ɗ/ and the palatal /j/ (like hoɗ- ‘suck’, ɗoɁ- ‘explode’ and moɁ- ‘win’), behave differently conjugating when they take any consonant initial morph and hence the agreement markers of such forms. They are not followed by a consonant. Based on this, when a suffix that begins in consonant is to happen on a verb root or stem that ends in one of these segments, they are deleted and followed by the preceding vowel length. However, in some cases the preceding vowel may be changed. The following table can make it clearer.
As Table 34 indicates, a marker that begins with consonant causes deletion of the terminating glottal segments `and others /j/ and /ɗ/which is followed by the preceding vowel length. Such form does not occur with 1sg, 3sgm and 3pl subjects because the conjugational agreement morphemes of these subjects do not begin with consonant; there is no change with status of the vowel  because  the   morphs   appended  are   vowel   or
Vowel initial.
With regard to the verbs that may also change their preceding vowels usually from low a into the high mid vowels. This occurs in both transitive and intransitive verbs. Example, gaj-s-e®geesse ‘she reached’, ɗaw-n-e®ɗoo-f-n-e ‘we weaved’, kaaj-s-e ® keesse ‘she put’. These can be considered as irregular verbs since their inflectional forms are special. Phonological process of total assimilation accounts for the change of the palatal segment /j/ into /s/. What makes these forms irregular is that they not only change their consonant which might be attributed to phonological process but also vowel change occurs. On the other hand, the low vowel can be realized as back, high-mid vowel being in length and the segment f happens by phonological process of partial assimilation in its conjugation as in ɗaw-n-e ® ɗoo-f-n-e ‘we weaved’, in which the change of vowels from low a into high-mid vowels is subject to irregularity. Therefore, they tend to be construed as irregular verbs.  
Verb stems are formed by several markers including the passive -am-, the causative -s- or -si(i)s, and the autobenefactive or the middle voice /-at-/ suffixed to the verb roots or other stems. The conjugational forms might vary across different types of verbs.
Table 35 shows that verb stems are inflected by occurring with the markers of grammatical functions that occur following the derivational suffixes. Autobenefactive verbs show distinct conjugational form with 1sg subject in occurrence of agreement morphemes in verbs. The autobenefactive verb with this subject is suffixed by the morpheme -ɗ- as its agreement marker. Mohammed and Zaborski (1990: 22) considers -aɗɗ as a morpheme of reflexive, middle voice and hence autobenefactive which is appended to verb root. However, I argue that the agreement marker should be considered here, because if we consider -aɗɗ itself as one morpheme it could be difficult to stripe the roots out on the verb forms like ňaat-ɗ-e‘I ate’ which distinctly shows the functional differences of the morphemes. The agreement autobenefactiv/middle voice suffix is -at which undergoes phonological process of assimilation with the agreement marker -ɗ-. The suffix -ɗ- shares its features to the final /t/ of the marker -at as bitat-ɗ-e®bitaɗ-ɗ-e ‘I bought:ABen’. The occurrence pattern of these markers is regular in that way with such verbs.
Different inherent and agreement grammatical categories account for the inflection of verbs in Oromo. The inherent ones are aspect, mood, and voice whereas the agreement properties include person, number, gender and case. Several studies, especially the earlier ones, consider tense in the inflectional categories of verbs in the Oromo language (Hodson and Walker, 1922: 29; Nordfeldt, 1947:117; Launhadt, 1973: 71; Gragg, 1976: 189; Mohammed and Zaborski, 1990: 7; Griefenew-mewis, 2003: 72ff). From the three major tenses present, past and future, Oromo mainly identifies between past and non-past in its morphology, because the morphological markers do not distinguish each tense types. For example, present and future tenses are not distinctly marked in the morphology of the language when tense is considered. Owens (1985: 82) distinguishes between past and imperfective in which the imperfective conveys present and future tenses. Therefore, the morphological distinctions that are overtly marked on verbs point to aspect rather than tense (Dabala and Meyer, 2003: 162; Kebede, 2009: 41). However, some extent of tense related concept is also found in the Oromo language. Some grammatical forms need tense-wise consideration which can be categorized under the two aspect types.
Inherent inflectional properties of verbs
Booij (1995: 2) identifies verbal inflection as tense, aspect, mood and voice adding that the important categories are three being tense, aspect and mood. The three main functional domains of inherent verb inflection in the Oromo language are aspect, mood and voice with some indications of tenses.
Comrie  (1976: 3)  states,  “Aspects  are   different   ways of viewing the internal temporal constituency of a situation”. According to his view, in aspect languages, perfective aspect has relation with inchoative forms that it conveys state changes. Aspect is context related which morphologically distinguishes between completeness and incompleteness of an action. It is bound with situation and duration unlike tense which is just about time of an event in relation with the speech time. In the Oromo language the roots or stems of verbs, usually ending in consonant, take inflectional morphemes showing distinction between perfective and imperfective aspects (Dabala and Meyer, 2003:162). Heine (1981), as stated in Kebede (2009:41), notes, “these two aspects are distinguished primarily by their suffix vowel, which is -a (and its allomorphs -i and -u) for the imperfect and -e (and its allomorph -i) for the perfective.” The continued actions are categorized as imperfective aspect whereas a short and completed action can be considered as perfective aspect. Dehl (1985) as stated in Bybee and Dehl (1989:84) says a perfective verb denotes a single event that happens which is seen as a whole regardless of duration. In their two major parts showing past and non-past, Oromo verbs are marked for such distinction of aspect. Perfective aspect can, of course, be illustrated in connection with a sense of past tense. The concept of perfectness is that an action is prior to a specific moment in time whereas the imperfectness is connected with an action in process or in progress.
[16]  išee-n        hoǰ-ičča    t’umur-t-e
she-Nom   work-Sing   finish-3sgf-Perf
‘She finished the work’
The perfect form indicates an action is complete at a specific time in the past as in example [16]. Imperfective aspect indicates a longer lasting action as in ɗufaa ǰira ‘he is coming’. When an action in progress is indicated by applying an auxiliary verb, it occurs with a sense of existing in some kind of experience. Therefore, the marker-aa of progressive suffix is appended to the action verb in its semantic compatibility with the auxiliary as. The progressive marker -aa seemingly a verbal noun is converbally used in Oromo being grammaticalized for present progressive form (Banti, 2003). Oromo identifies between past and non-past which can be considered in aspectual property. The markers of perfective and imperfective aspects -e and -a respectively occur on main verbs. When tense is considered, the perfect tenses and progressive tenses occur with auxiliaries ǰir- (present form) and tur- (past form) with their forms of agreement in inflection. Hence, the agreement markers are suffixed to the auxiliary verbs. The auxiliary verb always follows the main verb in a sentence. The aspect is, mainly, noticed on the converbal or progressive verb forms. The difference between perfective and imperfective is marked on the main verbs, so that when the auxiliary verbs are used, the converbal forms with the auxiliaries distinguish between and imperfective aspect in connection with tense (Table 36). The markers of perfective and imperfective aspects are -e and -a on action verbs respectively. The converbal form with -ee as in ɗuf-ee ‘come-Conv’ is perfective whereas the progressive form with -aa as in ɗuf-aa ‘come-PRG’ is imperfective with tense considered. Look at the following examples in sentences.
[17] (a) Fufaa-n        mana       bul-ee                                 ǰir-Ø-a
Fufaa-Nom   home      spend night-Conv:Perf        Aux-3sgm
‘Fufa has spent the night at home.’
(b) Fufaa-n         mana       bul-ee                               tur-Ø-e
Fufaa-Nom     home     spend night-Conv:Perf       Aux-3sgm
‘Fufa had spent the night at home’
As in examples [17] (a), the perfect form but present is like present perfect tense form provided by auxiliary verbǰir- ‘exist’. The converbal forms bulee ‘spend night-Conv’ determines aspect of the sentence. Both of the sentences (a) and (b) above are perfective aspect based on the forms of the converbs, and the perfective aspect marker -e is noticed on those verbas. Utilization of the auxiliary verbs shows the sense of tense. Considering the final vowels of the auxiliaries in aspect distinction is irrelevant. Shifting the converb marker-ee to the progressive marker –aa changes the aspect of both sentences into imperfective aspect in the same construction. What determines in the aspectual distinction is the inflectional form of the action verb occurring before the auxiliaries in a sentence. In progressive and perfect tense forms, when the first person singular noun or pronoun becomes  subject  of  a  sentence  the obligatory
agreement marker -n follows the lengthened forms of the markers of converbal construction as in mana bul-ee-n tur-e ‘I had spent the night at home’. The agreement marker -n functions to keep the meaning of the sentence if the independent subject pronoun is left out. The subject is understood from the verb suffix. The occurrence of the suffix -n is for the purpose of the subject agreement. Different forms of sentences in perfective aspect can be the same in their negative constructions. For example, the sentence Fufaan mana hin bul-n-e [bul-le] ‘Fufa did not spend the night at home’ is the negative form for different forms in the perfective aspect. It is formed by the preverbal negative particle hin and the dependent suffix on the verb -n-. Both of these elements are used together at the same time. Table 37 shows the suffixal vowels -e and -a, essentially, distinguish perfective and imperfeciive aspects as is noticed in the Oromo language. However, the allomorph -i is used with 2pl and 3pl subjects for perfective aspect marking. On the other hand, -i marks imperfective aspect when it is used with 3sgf subject, and the suffix -u is an imperfective aspect marker occurring with 2pl and 3pl subjects. Therefore, the markers -i, and -u are allomorphs of the aspect marker –a occurring in complementary distribution whereas the marker -i occurs as allomorphic variant of -e for perfective aspect. When the auxiliaries are used in the perfect and progressive tenses, the auxiliaries are followed by converbal form of main verbs, and aspect is also shown on the converbal or progressive verb forms.
Mood is the attitude of the speaker towards an utterance.
It is originally from the word ‘mode’ which means a specific way of doing something. Modality, which is also originated from ‘mode’, is more ideal and is about the existence of a particular way of speaking. According to Arin (2003: 15), modality is connected with the involvement of the speaker’s attitude and non-factivity in any utterance whereas the factive is truth or reality. In connection with the styles of speech which arises from involvement of feeling, Oromo has several types of moods from which four modal forms indicative, imperative and jussive are considered in this work.
Indicative mood: which involves making statements and asking questions constitutes the most common clause type in Oromo. In its construction, yes/no question is similar with declarative sentence except the final vowel length along with intonational relevance on the question form (Debela and Rooney, 2003:182). 
[18]Boruu-n          kitaaba         barreess-Ø-e
Boruu-Nom      book:ABS      write-3sgm-Perf
‘Boru wrote a book’
The subject is placed at the beginning of declarative sentences as in examples [18]. However, in interrogative sentences also, the subject is placed at the beginning. What makes interrogative is intonational variation. Actually, the subject can be placed either at the beginning or at the end of a sentence in both declarative and interrogative sentences. This is a kind of topicality shift from subject to object or theme in syntactic consideration.
Imperative mood: In Oromo, the imperative begins by the object as it precedes the  verb  in  word  order  of  the language. Intransitive verbs are used at the beginning of the sentence in the form of the subject ‘you’ understood. However, it may happen following motion verbs like deemuu ‘to go’ or kaɁuu ‘to stand’ in their converbal forms. The motion verbs often precede the objects of transitive verbs, and they happen in the terminating vowel length. 
A verb in its agreement form of number may occur at the before an imperative verb. Such form of verb is used in a converbally marked verbas in kaɁ-ii deem-i ‘stand and go-2sg:Imp’, it can be followed by either an intransitive verb or an object of a transitive verb.
[19]kitaaba       sana            fid-i
book:ABS   that:ABS      bring-2sg:Imp
‘Bring that book’
Sentence [19] implies that an object in its absolutive form often occurs at the beginning of imperative sentences. Modifiers of the object may occur following it as sister words in the noun phrase in the object form. In addition to verbs and objects, modifiers of verbs (adverbs) may also occur at the beginning of an imperative sentence as in ǰabeess-ii k’ab-i ‘catch firmly’. When the modifiers or other verbs begin the imperative verb, they agree with the subject in harmony with the imperative verb. Imperative verbs are also inflected by suppletive form using a completely different word of inflection. For example, the word koott- ‘come’ which is inflected for singular and plural number by the markers -u and -aa respectively is used only in the imperative form. The verb ɗuf- is not used in imperative construction but in the indicative form.  The verb root koott- is an imperative form of the verb root ɗuf- ‘come’ (Table 38). After it becomes in imperative mood by inflection through the use suppletive form, it identifies between the understood subject 2sg and 2pl form by agreement markers -u and -aa respectively. This suppletive form is typical to imperative form whereby the other modal forms occur with the verb root ɗuf- instead. Therefore, occurrence of the verb ɗuf- in imperative form is ungrammatical as in *ɗuf-i ‘come-Imp’. In affirmative imperative sentences, the converb agrees with the subject in number and occurs in harmony with the imperative verb in its final vowel.
Negative forms of verbs in imperative sentences occur in a little bit special way. The particle hin and the dependent suffix -n both mark negativity. The suffix -aa marks mood and plural number the verb of an imperative form.
Table 39 indicates distinct forms of imperative verbs in their affirmative and negative occurrences. It shows that in the positive form, imperative mood with singular subject is marked by -i- and -u on ordinary verbs and autobenefactive/middle verbs respectively. When plural subject is used, the marker of mood together with number will be -aa for normal verb and for the autobenefactive and the middle voice ones. The markers –u and -aa in positive imperatives occurring with autobenefactive verbs are  preceded  by  the  morpheme  -ɗ- which   marks   the mood being with the agreement markers. In the negative forms of imperatives, the same marker -i- marks the person, number and mood occurring before the dependent negative suffix when singular subject is used. The same way applies for autobenefactive or the middle verbs. However, a plural subject along with mood is marked by -aa which is appended after the dependent negative suffix -n for both the autobenefactive and normal verbs. 
When a verb occurs at the beginning of the negative imperative form, the converbal form marked by -ee or -ii is used. The terminating long vowel on the converb functions for identifying singular and plural numbers respectively. The interesting point is that in the negative form of imperative mood with plural subject, the second person singular marker -i-seems to be still occurring as in Table 32. Its function seems, but, no more related with person, number and mood marking, it will change to be like an epenthetic element for keeping the occurrence of the dependent suffix -n after vowel (which will be lengthened); for example, hin k’ab-n-aa ® hin k’ab-i-n-aa ‘Don’t catch-Ep-Neg-2pl’ in which the vowel -i has the function of epenthesis. 
Jussive Mood: Debela and Meyer (2003: 182) states that imperative and jussive have semantic and morphological features in common. Jussive mood is marked by the pre-verbal particle haa and the dependent suffix -u or -i on the verb. They co-occur in a sentence to mark mood and aspect. The suffixes mainly mark imperfective aspect. This construction is, however, rather syntactic. Here are few examples:
[20] (a) gurb-ičč-i           haa      ɗuf-Ø-u
boy-Sing-Nom   Juss     come-3sgm-Impf
‘Let the boy come’
 (b) isaan           haa       ɗuf-an-i
they:Nom    Juss      come-3pl:Impf
‘Let them come’
Jussive sentences are constructed with the types 3sgm, 3sgf, 1pl and 3pl subjects. All the subjectsin the jussive sentence occur in the nominative case. Examples [20] (a) and (b), indicate that the suffixes co-occurring with the preverbal particle haa are -u and -i that are used with singular and plural subjects respectively. Jussive mood is basically conveyed in the preverbal particle haa in the syntactic form.From the seven pronouns in Oromo, four of them, as mentioned above in comment of examples [20], are constructed in jussive form whereas the two second person singular ati and plural isin are in imperative form. The first person singular pronoun ana ‘I’ does not occur in jussive form. Here are few examples:
Negative forms of the jussive sentences is similar across the pronouns used which means the verb in the negative jussive doesn’t occur agreeing with subject in number and person. The negative jussive sentences are formed by the proclitic hin along with its coexisting dependent suffix -n on the verb. First person plural subject occurs only in positive jussive form.
The suffix –u and its allomorph -i, occurring with the preverbal particle haa, marks jussive mood in positive construction. The morph -u is suffixed to verb root or stem with 3sgm, 3sgf, and 1pl subjects whereas -i occurs with 3pl subjects in jussive mood (Table 40).   
In positive jussive forms the verb occurs in agreement with the subject in number and person whereas in negative, it doesn’t distinguish among the subjects. The form hin deemiin which literally means ‘don’t go’ is used with all the three person types except with the first person plural one. Of course, negative form in the jussive mood is rare and situation based in which this expression might occur in giving a negative response to the question haa deemuu? ‘Shall we let him go?’ whicn will be  hin deem-i-
nNeg go-Juss-Neg ‘don’t let him go’. Before the dependent negative marker -n, the vowel –I marks jussive mood being supported by the context.
Voice is a verb form that relates action of a verb with its participants (or arguments). It tells us if the subject performs or receives the action indicated by the verb. When the subject performs the action the voice is active whereas the form in which the subject receives the action is passive voice. Using sentence types in which the verb form is changed for the purpose of such grammatical function is inflectional. According to several theories like Government and Binding theory and minimalist approach, passive formation is a syntactic process in which the subject object exchange happens so that subject in active becomes object in the passive form and vice versa. The lexical-functional approach treats passive formation as a morphological process. Being in favor of the Lexical-functional approach, Wondwossen (2012:10) considers that passive formation in Oromo is purely morphological as it is formed by adding the morpheme -am on transitive verbs. Based on the Lexical-functional approach, this thesis treats voice as morphological form in inflection. The passive morpheme -am, in Oromo, is an invariable morpheme across subjects and aspects. Voice involves all valency changing verb forms including causative and middle; however, my consideration in this thesis is the most common ones – active and passive forms. Here are few examples in Table 41.
In Table 41, the examples indicate verb forms for voice change in perfective aspect. In both perfective and imperfective aspects, the morpheme -am- invariably marks the passive voice in contrast with the unmarked active form. The verb form contains the morpheme -am in its passive voice. Although lexical-functional approach is applied and hence morphological inflectional occurrence of voice is dealt with, in the syntactic consideration, the demoted agent subjects become object with the suffixed instrumental marker -n which occurs after vowel length in passive construction.
Copular constructions
A copula is a kind of verb that functions to link a subject with predicate nominative or predicate adjective. The invariable copulas in the language are ɗa and its negative form miti. Other copulas -ti (in genitive constructions) and -i (with nouns that end in consonant) are also functional in the language. In addition to these copular words or suffixes, the final short vowels on some nouns and adjectives can be considered as copula in the language. Nominas that end in short vowel, especially, in –a are understood for the covert copula in sentences  as  in  nuti tokko ‘we are one’. Zero morpheme in the Table 42 is to indicate that the copula is understood in a sentence to exist with no any phonological form. The vowel -i is a copula on -C final nominal which can formally and functionally be identified in the language, Oromo. According to Debela and Meyer (2003: 172), the copula -ɗa is a focus marker. It states that direct objects are marked for contrastive focus by the copula -ɗa, and adjuncts are also used with this copula in focus indication. As can be seen in Table 42, the function of the copula -ɗa is pervasively for focus marking except after long vowel in which its occurrence is obligatory the function is linking the subject to the complement. Therefore, the final short vowels can be considered copula whereas the copula occurring with such forms is contrastive marker of predicate adjective or object the copular verb itself. Ishetu (1981: 9ff) treats -ɗa as a morpheme with allomorphic occurrence with -i, -ti, and Ø, but it is a morphological copula that functions as focus marker being a verbal nature semantically.  
When -C final nominal is suffixed by -i and -ɗa at the same time, it will be clear that the vowel -i is copula, and the copula -ɗa is functionally shifted to focus marking. This is because the copula -ɗa is optional element and it does not bring meaning change if it is removed. The remaining -i makes sense of copular function in the presence of -ɗa and in its absence. We can also understand this from occurrence of the negative correspondent of -ɗa which is miti. It does not occur with vowel -i at copular position, *kun bišaan-i-miti ‘This is not water’ because both are copulas that they cannot be used together. The negative copula can be used instead of all the positive copulas.
 [21] (a) kun               bišaan-i
this:Nom     water-Cop
‘This is water’
(b) kun               bišaan-i-ɗa
this:Nom      water-Cop-Foc
 ‘This is water’
These two sentences in example [21] (a) and (b) are the same in content, except the focus phenomenon that the copula -ɗa adds on sentence (b). The positive copula ɗa occurs in the function as verb when it follows long vowel.
The copula -ti occurs in genitive construction only so that it is in complementary distribution with the other copulas mentioned above. Ishetu (1981: 12) indicates that the morpheme -ti is a copula used in genitive construction, and it is contrary to analysis of Gragg (1976: 183 which considers it as optional possessive marker. Owens (1985: 105) considers -ti as an intrusive element following genitive case marker (vowel length). This work is on the side of Ishetu (1981); the copular variant -ti has the function of linking a genitive nominal in the predicate with a subject. It can be used twice if the double genitive forms are noticed in a sentence.
[22] kun   [mana     [abbaa    koo-ti(i)]-ti]
this:Nom      house    father      my-Cop     -Cop
‘This is the house of my father’
The double genitive form in a sentence makes the copula -ti to be duplicated with the number of the genitive forms in Wallaga Oromo. This shows that the copula is tied with the genitive marker as in example [22]. It seems that the negative copula miti also occurs in the same way taking the place of the second copula as kun [mana [abbaa koo-ti] -miti]. However, in dialectal variation, only one copula is also used.
Agreement properties of verbs
Agreement, which can be construed as an instance of inflection, is a change in a form of a word depending on the other word/words to which it relates. Several grammatical features are marked by agreement properties. The agreement inflection occurs on a word when it is triggered by the grammatical categories that do not refer to its domain of the inherent inflectional/ grammatical categories. Inflection of agreement occurs based on the context of a sentence and it is an additional marker to corroborate (or confirm) the argument used. Booij (2009:7) states that a contextual inflection tends to be peripheral to inherent inflection. Therefore, the contextual or agreement properties function to confirm the appropriateness of relating the syntactic arguments and the theme of the verb on the basis of the grammar of a particular language. Verbs are marked by different agreement markers in Oromo.
Suffixes of agreement in Oromo
Oromo is a suffixing language in which other affix types do not exist. Its agreement markers are for the subject agreement only. Kebede (2009:43) considers that verbs are marked for person by -n (1pl), -t (2sg) and -ti (3sgf) on roots or stems. However, the agreement morpheme for third person singular feminine is rather -t instead of -ti. The verb occurs in agreement with subject in person, number and gender in Oromo. Zero morphemes are also used on verbs for some properties especially for third person singular masculine subject agreement. Some agreement properties are indicated by syncretism in which different grammatical functions are marked by the same form.
Table 43 shows the agreement between the subject pronouns and verbs by the markers suffixed on a verb. For the plural person types (subjects), the verb is marked for agreement separating person and number unlike the singular subjects whose agreement morpheme represents both person and number features of agreement. The two way agreement marking, as seen in Table 43, is clearly noticed on 2pl subject that marks person and  number  by distinct morphemes -t- and -an respectively. 
The first person singular pronoun shows special occurrence of agreement. The pronoun suffix occurs, especially, with copulas and auxiliary verbs and in progressive tense forms. It can be marked on verbs by zero morpheme whereas it is also marked by -(a)n appended on verbs or on other word types in predicate. For example, mugaa-n ǰira ‘I am slumbering’. In this sentence, the subject is understood to be ‘I’ from the suffix -n on the progressive verb. It’s clear that subject agreement on verbs is realized verb internally that is before aspect markers; however, 1sg pronoun can occur at the final position of verbs. Of course, it does occur not only with verbs but also with different word categories in the predicate phrase. Debela and Meyer (2003: 179) states that the morpheme -(a)n is an agreement marker for first person singular subjects. It seems that the suffix -(a)n is the pronoun itself behaving as a morphological element appended to different word classes in the predicate phrase. Wherever it occurs, its function is distinguishing the subject in the form of agreement.
Table 44, all the words occurring with the morpheme -(a)n are different either in word category or in their paradigmatic function though some of them are clearly distinguished when they are put in sentence. Here is one example sentence:
[23]    an-i    barataa               č’imaa-n     fil-e
I-Nom    student:VN      strong-1sg         select-Perf
‘I selected an intelligent student’
The suffix -n on the adjective č’imaa ‘strong’ in example [23] functions as an agreement marker for the subject. In such occurrence of the morpheme -(a)n in a sentence, the presence of the subject an-i ‘I-Nom’ is not obligatory as the morpheme distinguishes it. It occurs just for emphasis of the nominative case. When two converbs occur in a sentence, the agreement marker of first person singular subject can occur on either of them.
[24] deem-ee ilaal-ee-n deebiɁ-a
go-Conv       watch-Conv-1sg      return-Perf
‘I will go, watch and come back’
In example [24], the first two verbs are in converbal construction either of which can be suffixed the 1sg marker -(a)n. In Wallaga Oromo, the form ilaal-ee-n‘watch-Conv-1sg’ can also be used as ilaal-ee-t-an ‘watch-Conv-Ep-1sg’, in which the epenthetic consonant -t- is inserted between the converbal suffix and the pronoun suffix when the the morpheme begins with the optional vowel -a- which can be varied to -i- as in bor-in ‘tomorrow-1sg’ (dialectal). The morphemic pronoun -(a)n can also occur with functional words like the focus marker hin which marks action of a verb in focus. Several studies like Baye (1988: 368); Debela and Meyer (2003: 166) state that the preverbal element hin marks focus on the verb seemingly obligatory with intransitive verbs in declarative sentences. My point is apart from explaining focus marking systems; but it is to show the relation between hin and nan both occurring preverbally  to  avoid
the confusion in the functional and formal occurrences between the two. 
The preverbal element nan is formed from combination the reducible focus marker (h)in and the 1sg marker -(a)n under phonological processes of deletion. It forms up a portmantou [nan] by combining the two separate elements.
(h)in ‘Foc’ +(a)n ‘1sg’ ®inan® [nan]
It means, the preverbal element nan portrays both focus and 1sg marking. This is because of several reasons: 1, the 1sg marker -(a)n can occur with different words in the predicate phrase (cf. Table 45) which means inclusive of the functional elements like hin. 2, the 1sg pronoun does not occur with the focus marker hin but with nan instead which means nan can replace the function of hin 3, the preverbal element nan restricts the subject whereas hin does not function like this. 
When nan occurs preverbally in parallel with the occurrence of (h)in, its function is focus marking in the obligatory form hand in hand with 1sg marking. Therefore, when the 1sg marker -(a)n is a 1sg pronoun marker which can also combine with (h)in for focus marking. Haimanot (1984: 9) considers nan as an obligatory prefix for first person singular pronoun in the same function with the focus marker hin though it does not describe its internal form in terms of function. However, it is, in my view, a portmantou like preverbal element containing both (h)in of focus and -an of first person singular pronoun.  
Autobenefactive and middle voice are marked by the suffix -at- in Oromo. Even though both are marked by the same morpheme, they are semantically distinct. The autobenefactive form indicates that a subject performs something for its own benefit whereas the middle voice is about an action that is more closely connected with the subject for the same function in being benefactive.
In Table 37, the morpheme -at- functions to mark an middle  verb  form  (Table 46),  because   the  action   is performed on the affected agent, though, it is for the purpose of getting benefitted. The same marker -at- indicates the autobenefactive voice in which the action is performed on another thing (compare with ABen – Table 35); the benefitted subject is more affected in the middle form than the one in the autobenefactive counterpart (Shimelis, 2009: 4). The morpheme -at- can be followed by the agreement marker -ɗ- with first person singular subject as inɗik’-at-ɗ-e®ɗik’-aɗ-ɗ-e ‘bought for myself’, or it can be followed by -n- with first person plural subject as in ɗik’-at-n-e ® bit-an-n-e ‘bought for ourselves. It undergoes phonological process of assimilation forming -aɗɗ and -ann respectively which seem to be variants of the autobenefactive or the middle forms. 
Adverbs in inflection
Basically, many adverbs are derived from other parts of speech in Oromo.  However, some words are fit to be categorized as adverbs (Nordfeldt, 1947:184). Almost all adverbs including the derived ones can be suffixed by -uma which makes the point of the adverb in focus. Example, as-uma tur-n-a [tur-r-a] ‘We will stay here’. Derived words from other parts of speech or phrasal forms are prominently used as adverbs in the language. Some stems derived from other word classes undergo inflection to agree with the subject in a sentence. The agreement marker is applied, particularly, on the adverbs that are derived from verbs.
 [25] inni          barfat-ee          ɗuf-Ø-e
he:Nom    late-Conv   come-3sgm-Perf
‘He came late’
The adverbs that occur in agreement with subject are those which are derived from verbs. They occur in harmony with verbs showing agreement with subject in person, number and gender. As example [25] shows, the adverbs occur in the form of converbs with final vowel length. 
Adverbs behave like nominal for that they can occur in nominative case taking the suffixes -i, -n and -ni of the nominative  markers.  During  this,  they  are  used as  an
adverbial noun subject. Adverbs are basically categories of predicate phrase that they cannot be treated in nominal inflection because they modify verbs. According to Baye (1986: 65) illustration, although adverbs are functionally verb restricting words, they behave like nominal taking markers of nominative case. It considers adverbs as part of nominals based on their inflectional behavior and that they occur with adpositions taking -f meaning ‘for’ as in harɁaa-f ‘for today’ whereas adpositions are basically occurring with nominals only.
Adverbs in the nominative case are used as nominal they occur with the nominative case markers as shown in Table 47. However, their basic function and lexical class is predicative that the function as verb modifiers which, obviously, can be categorized in the predicate phrase of a sentence.
Adverbs undergo inflectional morphology for the agreement


Oromo is a suffixal language in both derivational and inflectional morphology. The root form is usually meaningless and ends in consonant. Almost all word classes undergo inflectional morphology. Since several forms are indicated by the suffixes, there is a tendency to convey wider message in a short sentence that means fewer words may represent wider message in the language. A single morpheme has several grammatical functions as cumulative form. Syncretism and zero morphemes are significant, especially, in verb inflection. These are the tokens for justifying that the Oromo language is highly fusional, in which morphs are fused together for grammatical functions. Concatenation of the morphs seems complex. Inflection of nominals follows the system in which all sister words of a noun in a noun phrase are declined in the same ways with the head noun. Nominals are inflected for the inherent grammatical categories of number, gender and singulative along with the relational category, case. Both definite and indefinite nouns are not clearly and morphologically marked. Definiteness, though, can be conveyed under singulative markers having no any marker of its own. Masculine and feminine gender is distinctly marked by -icca and -ittii respectively for singulative property. Pronoun inflection is declined for the same grammatical categories with the noun and follows almost the same rule of inflection. However, it involves more complex morphemic elements and suppletive forms than that of nouns. Double usage of pronoun in the dative case is permissible in Wallaga Oromo; one is placed before the direct object for emphatic purpose and the other is after. First person singular pronoun can be considered to occur in special agreement inflection. The 1sg marker-(a)n occurs as a suffix on one of the word classes in the predicate part with a covert or overt subject. It is also suffixed to the functional element hin to form a portmantou like element nan combining hin and nan through phonological process as   (h)in + an ® inan ®[nan] which is used in parallel with hin as focus marker. Verbs distinguish between past and non-past and the forms indicate perfective and imperfective aspects in their inflectional morphology. A sense of tense also exists in the language though aspectual forms are more pervasive than tense. Agreement markers realized in verbs for plural subjects is two-way system in which person and number is separately marked by separate morphemes. This is contrastive singular forms in which one cumulative morpheme conveys both person and number features of agreement.


The authors have not declared any conflict of interests.


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