A comparative syntactic review of null-subject parameter in English and Ịzọn languages

The theory of universal grammar relies predominantly on the biolinguistic concept of natural endowment and innate knowledge of the general principles of language. It postulates that all humans are naturally endowed with the general rules and configurations of language and to this extent, all natural languages have similar structural features. The theory of universal grammar as hypothesized by Chomsky and propagated by other linguists not only recognizes the universality of the general principles of language but also the existence of language-specific idiosyncratic features that constitute parametric variations among languages. These are the parameters of universal grammar. The most prominent parameters that create distinctions between languages are head directionality, pro-drop or null-subject and whparameters. This paper reviews the null-subject parameter in English and juxtaposes its occurrence or non-occurrence in the Ịzọn language. The aim of the paper is to characterize the parametric choices by English and Ịzọn languages in the derivation of grammatically convergent sentences with null-subject constituents. The study is competence-based and used data from tokens of sentences in conversation among competent native speakers of Ịzọn language. Data from each language were translated into the other via a gloss and comparatively analysed. The study reveals that null-subject constituent is not a characteristic feature of English syntax but a feature of Ịzọn syntax. The study is significant because it contributes fresh linguistic data for the principles and parameter theory.


INTRODUCTION
Null-subject parameter is one of the most prominent parameters put forward in the related theories of universal grammar and principles and parameters grammar (PPT).Whereas, universal grammar postulates general principles of grammar shared by all natural languages which are considered to be innate to human beings (cf Baker, 2002;Radford, 2004a), principles and parameters hypothesize the general principles or abstract rules of grammar common to all languages as well as specific parameters or choices made by individual languages.Principles, E-mail: odingowei@ymail.com.Tel: +2348086713577.
Authors agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License in other words, are the syntactic features that all natural languages of the world possess, because, according to Chomsky (2002), "language is part of the mental biology (a natural endowment) of all humans".On the other hand, however, every language still possesses idiosyncratic peripheral features peculiar to itself.The idiosyncratic features are, actually, the parameters that give every language its distinctive identity.Parameters in the literature are characterized as having binary settings or that features have binary values from which natural languages make their parametric choices.This indeed is the basis for comparative syntax or contrastive linguistics.For these reasons, according to Newmeyer (2005), the principles and parameters theory has remained relevant in mainstream generative syntax.Radford (2004a) summarizes PPT as: a theory which claims that natural languages incorporate not only a set of innate universal principles which account for those aspects of grammar which are common to all languages, but also a set of parameters which account for those aspects of grammar which vary from one language to another (471).
Null-subject is one of the parameters of universal grammar.The concept of null-subject or pro-drop arises from the permissible dropping, in some languages, of subject pronoun of a sentence because of potential pragmatic recoverability from context.The content of nullsubject is phonologically and morphologically covert but is recoverable in context by competent native speakers of the language.A null-subject is said to have grammatical and semantic properties but lacks overt phonetic form.Going by the parameter of null-subject, some languages are classified as null-subject or pro-drop languages while some are classified as non-null-subject or non-pro-drop languages.English, according to Chomsky (1995) and Radford (2004a) is a non-pro-drop language, but Italian is a pro-drop language because it allows finite verbs to have null-subject in its syntax.
Pro-drop parameter has implications for language acquisition.This paper is a comparative review of the null-subject parameter involving English and Izọn languages.The aim of the paper is to characterize the parametric choices by English and Ịzọn languages in the derivation of grammatically convergent sentences with null-subject constituents.In other words, it describes how native speakers of the two languages acquire their languages through different parameters in the binary arrangement.The paper is hinged principally on theoretical linguistics which will provide linguistic information about the null-subject status of the two languages, which in addition could facilitate the learning of either of the two languages as L 2.

METHODOLOGY
The materials for analysis in this study are linguistic data.Data on English are collected from Standard English textbooks, while data on Ịzọn language consists of tokens of spontaneous utterances or naturally occurring sentences recorded from competent native speakers of the language.One of such occurrence was a discussion between two rural women which reveals null-subject constituents in some of the sentences.The data in Ịzọn has a word for word and/or morpheme by morpheme gloss and a translation in English.This process reveals glaring variations between English and Ịzọn.This comparative study is based mainly on qualitative analyses.

PRINCIPLES AND PARAMETERS OF UNIVERSAL GRAMMAR
The Null-subject or pro-drop parameter is a concept rooted in the principles and parameters theory of Universal Grammar (UG).This is a theory formulated by Chomsky (1981) and propagated by other linguists such as Radford (1997Radford ( , 2004aRadford ( , 2004b)), Webelhuth (1995), andLasnik (1995), among others.The PPT seeks to explain the similarities and variations that exist among natural languages.It identifies general principles possessed by all natural languages.These similarities include the lexical categories of parts of speech, the structural categories of phrases and clauses, the presence of (phrasal) among others.Apart from lexical differences, languages also vary in word order or syntactic structure.Smith (2005: 38), while explaining the diversity of languages in the proper perspective of PPT, states that "although languages differ along various dimensions, the principles and parameters have been there from the beginning and children are born with the principles with some specifications of the range of variations in possible human languages."Therefore, the child learning the grammar of any particular language has to find out the permissible values or parameters in his language.This is an affirmation of Chomsky"s (1982) postulation that: The grammar of a language can be regarded as particular values for the parameters available in UG while the overall system of rules, principles and parameters is UG which may be taken to be an element of human biological endowment, namely the "language faculty" (7).This means that a language is a system of specifications for usually binary parameters in an invariant system of principles of Universal Grammar.Therefore, as Ali (2007) explains, linguistic diversity is determined by a variation in the setting of certain values.In other words, parametric variations are determined by the parameterized choices languages make in different dimensions.They include word order, head directionality parameter, Null-subject or pro-drop parameter and whparameter.PPT is a useful instrument for CA since it concerns choices made by languages, as it will be seen in this study.For this reason, PPT is adopted in this study.

The structure of the English language
The English language, according to Chomsky (1995: 36) is a non-pro-drop language because the dropping of the subject in the sentence structure is not permissible.This is the syntactic parametric choice of the English language from a system of binary options.Consequently, a declarative sentence in English with a null-subject is considered by competent speakers of the language as ungrammatical, although, this is with the exception of imperative sentences which usually lack overt subjects.English is an SVO language; the canonical structure of a standard derivation in English is SVO consisting of the subject, verb and an object or adjunct as in the examples 1 and 2.
(1) He has bought a new car.
Although pro-drop is not permissible parameter English grammar, it is the parametric choice of Italian syntax.
According to Radford (2004a: 107), all finite clauses in Italian allow null-subject.Radford describes pro as a null finite subject in Italian.Therefore, all competent native speakers of the Italian language have acquired this syntactic parameter of Universal Grammar so that native speakers and hearers are able to decipher the meaning of not only overt codes but also of the empty categories, that is, the null-subject.Again, although English is not a null-subject language, it does permit pro-drop in imperative sentences and "truncated null subjects in colloquial spoken English" (Radford, 2004a: 106).Imperative sentences express commands, requests and prayers and are usually headed by a verb.It does not have an overt subject as in examples 4 and 5. Radford (2004: 107) refers to this as "imperative null-subject".In an imperative null-subject, the phonetic features of the logical pronoun "you" are not spelled out since it is not phonologically and morphologically realized, but Chomsky"s ideal native speakers and hearers possess the linguistic knowledge and competence based on the internalized syntactic rules of the language to recover, understand and interpret the unspecified meaning of the null-subject from context.

Null-subject manifestation in Izọn language
Ịzọn is a language spoken by the Izọn or Ijaw peoples who inhabit areas in the Niger Delta basin of Southern Nigeria.It has varieties in Kolokuma dialect, Arogbo dialect, and some pro-Ijaw or Ijoid languages such as Kalabari, Nembe, Ibani, Okrika, Defaka, among others.Kolokuma dialect is adopted in this paper because it is a central variety intelligible to speakers of other varieties.While the English sentence has an SVO structure, a finite clause in Ịzọn language has the canonical structure of SOV (Williamson, 1969;Kwokwo, 2012).This is in spite of the fact that the object and the verb remain constituents of the verb phrase (VP) and of course, the object remains and functions as complement of the verb.It is a syntactic reality that Ịzọn is a head-final language and this accounts for the assignment of accusative Case left-ward.This is the syntactic opposite of the English clause structure which is a head-first language.It may be noted that head-directionality, and indeed, casedirectionality are also parameter in UG and PPT (cf Ndimele, 1992).
It is also a linguistic fact that Ịzọn permits both overtsubjects and null-subjects in its sentence structure.Nullsubjects which, syntactically, are empty categories are found in all types of derivations namely, the declarative, imperative and interrogative sentence.This is to say that beyond the general principles of universal grammar available to it, the Ịzọn language also has the null-subject as an idiosyncratic or peripheral feature which serves as part of the component of (triggering) experience or stimulus in the process of language acquisition.Examples of both the canonical SOV linear structure and the pro-drop sentence are provided in the following.As mentioned earlier, the sentences above have overt subjects.These are the pronouns " mịnị" in example [6] and "Wòni" in example [7].However, these subjects may be elided or omitted by native speakers and the meaning is not lost on ideal hearers because their linguistic or communicative competence enables them to recover the semantic content null-subject and interpret the sentence.Pro beingbaị dengiyọ kọ munghimi-ó?Pro today, where to go + will?"Pro where will you go to, today?" A similar occurrence of parametric null-subject is observed in Speaker B2 utterance in response to Speaker A2.
Speaker B2: Fọụ kọ munghimi Market to go + will "I will go to the market." The subject of the sentence in Ịzọn lacks phonological and morphological form.The syntactic parametric suppression of the subject nevertheless does not make the sentence ungrammatical.Pro in this and other sentences has semantic content which is interpretable at LF, of Pro, it is mutually recoverable and interpretable to both speaker and hearer who have innate competence to decode the null constituent.Finally, the derivation of Speaker A3 reveals a covert subject in the subordinate clause with its complementiser at the end of the clause and an overt subject in the matrix clause.The tree diagram below the sentence illustrates the explanation that Ịzọn language permits both null and overt subjects.
"If you will go to the market, let us go together." Pro fọụ kọ munghimi aba, wȍ kẹnịtu mu.

Null-subject in interrogatives in the Ịzọn language
The interrogative sentence is one of the major types of sentence.They may either be yes/no questions or whquestions.Traditionally, interrogative sentences in English have overt subjects.For example, simple interrogatives such as "are you coming?" and "what are they doing?"have morphologically realized subjects.This implies that English does not permit null-subject in its interrogatives.However, null-subject is also a common syntactic feature of interrogatives in Ịzọn language as illustrated in the following sentences. (

Implications for language acquisition
The foregoing analyses show that while English is decidedly a non-pro-drop language.On the other hand, Ịzọn seems to be more linguistically flexible by permitting both overt subject and null subject.Carnie (2007: 416) explains that "the null-subject or pro-drop choice in some languages does not create ambiguity in communication ostensibly because children of those communities grow up with and acquire the null-subject parameter" since their language(s) is/are parameterized in that way.Consequently, all "ideal" native speakers and hearers of null-subject languages have no problem in generating an infinite number of grammatically correct sentences and interpreting them as well.
Why, indeed, do some languages opt for the nullsubject parameter instead of the overt subject parameter?Carnie (2007) is of the view that null-subject is used by languages with "rich" agreement or perhaps languages with "agreementless" syntax as in the case of Ịzọn; Ịzọn is a language that does not observe subjectverb agreement.
It is also curious that universal grammar has null-subject parameter but not null-object parameter.However, some linguists attribute the null-/overt-subject phenomenon to the language processing processes.For instance, Bloom (1990: 501, qtd. in Rizzi, 2004: 87) argues that "in language acquisition and processing, subjects are more likely to be dropped than objects because they occur earlier in the sentence."He rationalizes this early subject phenomenon with the argument that in the process of deriving a sentence, "the processing load of a language at the top (subject position) of the sentence is maximal.

CONCLUSION
The thrust of this paper has been the parametric variation between English and Ịzọn languages using the nullsubject parameter.Although, both languages possess the biological aspects of language, that is, the general principles of language which linguists call Universal Grammar, each language also has its own idiosyncratic features which differentiate them significantly because they are parameterized differently.In fact, a translation of a null-subject sentence in the Ịzọn language will be ungrammatical in English.Consequently, children in the two language communities grow up to acquire the parameters of their languages, in addition to the biologically endowed aspect of Universal Grammar.

( 4 )
Come here quickly (You, come here quickly) Wòni dụa fúnama fẹẹnghimi.We some books buy-shall."We shall buy some books." has bought a new car.These are convergent derivations in English because the subject position which is the Specifier of Inflection is not covert but overtly and morphologically realized.In other words, the grammatical and semantic properties of the subject are given phonetic form.But if these derivations are presented with a null Specifier of Inflection, they would become ungrammatical and unacceptable to native speakers or other competent speakers of English as shown example 3.
Odingowei 83understanding and interpretation of pro in Ịzọn is facilitated by the fact that Ịzọn syntax lacks subject-verb agreement as earlier noted in this essay.Let us at this point consider the data shown earlier in the methodology as reproduced in the following.
non-Ịzọn speaker in the sense that there is the possibility of interpreting pro to mean any other pronoun, competent speakers and hearers are able to elicit the appropriate pronoun by relying on the context of the communication.In the first place, the valiancy or sub-categorization of verbs provide for obligatory subject NP, not only in English but also in the Ịzọn language.Secondly, the