Turkish as a foreign language learners’ awareness and use of morphology in guessing the meanings of unknown words from context: A case study

This study investigated Turkish as foreign language learners’ awareness and use of Turkish derivational affixes as a knowledge source in guessing the meanings of unknown words in written contexts. In addition, this study also examined the type of knowledge sources used in guessing the meaning of the unknown words. The study was conducted with the participation of 10 B1(Threshold, Pre-intermediate) which is based on Common European Framework of Reference (CEFR) for languages, level students at the Turkish Language Teaching and Application Center (TÖMER) at Gaziosmanpasa University, Turkey. The data were gathered through think aloud procedures. The participants were asked to read a passage and try to infer the meanings of 10 target words that included derivational affixes. The participants were tape-recorded during the think aloud procedures. The tape recordings were transcribed in order to analyze the data gathered from the participants. The data analysis involved reading and rereading of the tape scripts. Then, knowledge sources were identified and classified, and the participants’ successful and unsuccessful uses of Turkish morphology were examined. According to the result of the study, Turkish affixes are not effective knowledge sources in determining the meanings of unknown words. Among the knowledge sources used by the participants, Discourse/Text knowledge had the highest percentage (52.0%) and grammatical knowledge had the lowest (0.0%). The result of this study suggests that Turkish suffixes especially derivational affixes had a minimum affect in inferring the meanings of unknown words in context.


INTRODUCTION
The notion that we learn a lot of our vocabularies through reading, or more particularly comprehensible written input, is now entrenched in second and foreign language teaching (Nation and Waring, 2004).Learners naturally encounter unfamiliar words while reading a text and use a variety of strategies to understand those unknown words.Stoller and Grabe (1995) pointed out that by becoming familiar with only a few stems, prefixes, and suffixes, students will recognize the meaning of many words; one root or affix can often provide a student with a E-mail: fatih.yilmaz@gop.edu.tr.
Authors agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License clue to the meaning of dozens of words.According to this idea, analyzing target word structure is one of the efficient ways to deduce the meaning of an unknown word in a text (Paribakht and Wesche, 1999).
Moreover, it is beneficial for students whose native languages are not related to the target language, to become aware of the similarities and differences of the two languages.Learners' native language is a salient factor affecting successful guessing.According to Nation (2001), an important factor affecting guessing from context is the similarity between the learners' native and the target language.If a learner's L1 does not have an equivalent of a word in L2, it may be difficult for the learner to guess the meaning of that word.According to Nassaji (2003) some foreign language learners refer to native language, when guessing unknown words.Lado (1957) assumed that the student who comes in contact with a foreign language would find some features of it quite easy and others extremely difficult.Those elements that are similar to his native language will be easy for him and those elements that are different will be difficult.Turkish language learners do not use a wide variety of guessing strategies except for looking up a dictionary and asking the teacher or their classmates for the meanings of unknown words when they encounter new words while reading.This study tries to discover Turkish as foreign language learners' morphological awareness and use of Turkish morphology as a knowledge source in attempting to guess the meaning of unfamiliar words in context.
It is almost impossible to learn a language without words; even communication, between human beings, is based on words.Therefore, teaching these words is a crucial aspect in learning a language.Both teachers and students agree that acquisition of vocabulary is a central factor in teaching a language (Walters, 2004).There are thousands of words in a language.Thus, vocabulary learning is a difficult process because it is impossible to attain mastery of all words in a language (Nation, 2001).Individual learners attempt to learn vocabulary in two ways; intentionally, through which learners learn vocabulary deliberately, and incidentally, through which learners learn new words from context.Learning from context may occur during extensive reading, while listening to stories, television, or radio, both in the first language and second language.Paribakht and Wesche (1999) revealed that most vocabulary learning occurs naturally when learners attempt to understand new words they hear or read in context.Similarly, Coady and Huckin (1997) claimed that much foreign language vocabulary learning occurs incidentally while the learner is engaged in extensive reading.Empirical studies demonstrate that reading is an effective way of learning new words (Ercan, 2009;Lau and Rao, 2013;Senoo and Yonemoto, 2014).
Through the reading process, learners encounter many unknown words.In order to overcome this problematic part of reading, learners use a variety of strategies to discover the meaning of an unknown word.Learners can use several strategies, such as using a dictionary, receiving help from the teacher or peer, or parsing the meaning of a word from its context, to facilitate the learning of new words (Harley and Hart, 2000;Qian, 2004).Among these strategies, dictionary use and guessing strategies are widely used.According to Nation (2001), learning vocabulary through guessing from context is the most important of all sources of vocabulary learning.Many educators encourage the contextual guessing strategy, which refers to the use of background knowledge and linguistics cues to infer the meaning of unknown words (Kaivanpanah and Alavi, 2008: as cited in Huang and Eslami, 2013).If learners do not know a word, they discover its meaning by guessing from structural knowledge of the language, guessing from an L1 cognate, guessing from context, using reference materials, or asking someone (Schmitt, 1997).By and large, lexical inferencing involves the use of linguistic cues in combination with the learners' general knowledge of the world, their awareness of context, and their relevant linguistic knowledge (Haastrup, 1991).
There are certain sources of information L2 learners frequently refer to when guessing from context.The first one is the use of sentence level grammar, from which learners deduce the syntactic category of the word.Another knowledge source used by L2 learners in order to infer the meaning of unfamiliar words is word morphology.Learners' knowledge of L2 word morphemes (i.e.stems, and affixes such as -cı, -lık, -sız) enables them to deduce the meaning of an unknown word.Third, learners' familiarity with the topic and theme is an important source of clues for inferring the meaning of unknown words (Pulido, 2007).Cognates are another influential factor in the guessing process.Related languages abound in cognates, such as German buch, Danish bog, and English book.Interlingual cues in a text such as loan words or cognates, and any other kind of transfer between the native language and the target language are some of the features that are available for use in inferring the meaning of unknown words from context (Carton, 1971).Intralingual clues pertain to the features of the new word and the inference maker's reliance on his/her information about phonology, orthography, morphology (the meaning of stem, prefix, and suffix), word class and collocations to guess the meaning (Riazi and Babaei, 2008).In addition, learners use their knowledge of sound relationships or the phonetic similarity between the target word and another word in the learners' mental lexicon to guess the meaning of an unknown word (Paribakht and Wesche, 1999).
A number of factors affect students' attempts to infer the meaning of unfamiliar words.First, text characteristics influence learners in terms of both their motivation and their success in guessing the meanings of unknown words.For example, according to Paribakht and Wesche (1999), theme-related texts appear useful for vocabulary expansion because words appear repeatedly and take on salience, thus enriching the meanings from varied contexts.
In addition to that, the text should have a manageable difficulty level (Paribakht and Wesche, 1999).Second, cultural familiarity with the text helps learners understand the text better.Vocabulary gains are greater when participants read culturally familiar texts (Pulido, 2004).Third, word characteristics are also influential in guessing the meaning of an unknown word.Some words look as if they are composed of meaningful morphemes (Laufer, 1997).Frequency of occurrence of a word is another important factor when attempting to guess the meaning of unknown words.Sternberg (1987) pointed out that multiple occurrences of an unknown word increase the number of available cues when attempting to guess the meaning of an unfamiliar word.Another important factor affecting guessing from context is individual differences.More proficient learners are more successful guessers and use a wider variety of guessing strategies than those who are less proficient (Paribakht, 2005).In addition, a critical level of vocabulary knowledge is essential for successful use of guessing strategies (Laufer, 1997).
Finally, native language is influential on the word guessing process.Learners of related languages are more advantaged than the learners of unrelated languages.Nation (2001) claimed that the similarity between the learner's first language and the second language is an important factor affecting guessing from context.Of all the guessing strategies, morphological knowledge as a strategy has an important role in reading and inferring the meaning of unknown words.Paribakht and Wesche (1999) demonstrated that learners' knowledge of L2 word derivations (e.g.stems and affixes) is the second most important knowledge source used in inferring the meaning of unknown words.Furthermore, Nassaji (2003) demonstrated that students use world knowledge most frequently, and the second most frequently used knowledge source in attempting to derive the meaning of unfamiliar words is morphology.

Statement of the problem
Incidental learning by means of guessing from context is the most important source of vocabulary learning (Nation, 2001).Learners use a variety of guessing strategies when attempting to guess the meaning of unknown words.For instance, Carlisle (2003) pointed out that morphemic awareness might be regarded as an analytic skill that involves inferences about word structure and meaning.Developing morphological awareness may become very important for readers (Carlisle, 2000).However, there have been very few studies (Mori, 2003;Parel, 2004) on the roles of L2 morphological awareness in reading.Parel (2004) also asserted that very little is known about the relationship of sensitivity to word structure to reading achievement in the second language.There has been little empirical study of Turkish as a Yılmaz 677 foreign language learners' awareness and use of Turkish affixes when making inferences about unknown words in written contexts.In addition to that, there has been no study comparing Turkish language learners' awareness, use of suffixes appearing in unknown words and knowledge sources in guessing the meaning of unknown words.But there are studies which deal with the handling of unknown vocabulary and knowledge sources in teaching English as a foreign and second language.Akpınar (2013) examined English as a Foreign Language Learners' (EFL) handling of unknown words while reading English texts and focused on the question of whether the English language learners are aware of the strategies and knowledge sources they apply while guessing the meanings of the unknown words.Turkish EFL learners handle unknown vocabulary in various ways.Among other strategies such as consulting a dictionary for their meanings, attempting to infer their meaning from context is a popular way of handling unknown vocabulary by the learners.İstifçi (2009) examined the lexical inferencing strategies of Turkish EFL Learners and the result of this study revealed that the students at intermediate level were more successful than the students at low-intermediate level in their guesses of the meaning of unknown words.
Turkish as a foreign language, one of the less commonly taught languages, differs considerably from more commonly taught languages such as English, French and German.In the foreign language classrooms, vocabulary acquisition has long been a central issue for students as the grammar based main course book and the skills books are filled with new lexis that the students must acquire.However, the Turkish language learners do not use a wide variety of vocabulary learning strategies except for looking up a dictionary for the meanings of unknown words when they encounter new words while reading.
Similarly, foreign students at Gaziosmanpaşa (GOP) University do not use many of the vocabulary learning strategies in reading classes apart from looking up a dictionary and asking the teacher or their classmates.The reason for this situation could be that the students may not know most of the guessing strategies and they may not be aware of the role of Turkish morphemes as a clue to decode and infer the meaning of unfamiliar words.Moreover, the students might not be aware of many features of Turkish morphology.In this study, whether the Turkish language learners at (GOP) University use Turkish affixes as a knowledge source to infer the meanings of unknown words encountered in written contexts and whether they use knowledge sources in guessing the meaning of unknown words are investigated.

Significance of the study
There is limited research on Turkish as a foreign language students use of morphological cues as a knowledge source in attempting to infer the meanings of unfamiliar words in context.Thus, this study might contribute to the literature by providing a description of how or whether Turkish as a foreign language learners use morphological cues in inferring word meaning from context and which knowledge source has been used widely in guessing the meaning of unknown words.
At the local level, this study will be the first on foreign students' awareness and use of Turkish morphology as a knowledge source in order to guess the meanings of unfamiliar words in context at Gaziosmanpaşa University.This study may be beneficial to Turkish as a foreign language teachers and students in developing strategies for dealing with unknown words containing affixes.

METHODOLOGY
This study investigates the awareness and the use of Turkish suffixes by Turkish as foreign language learners in guessing the meaning of unfamiliar words encountered in written contexts and to find out which knowledge sources have been used in guessing the meaning of unknown words.

Research questions
1. To what extent do Turkish language learners refer to Turkish derivational affixes in order to guess the meaning of an unknown word in written contexts?2. Which knowledge sources have been used in guessing the meaning of unknown words?

Setting
This study was conducted at Gaziosmanpaşa University Turkish Language Teaching and Application Center (GOÜ-TÖMER).There were 29 currently enrolled students at GOÜ-TÖMER at 2014-2015 academic years.The students were at intermediate level when this study was applied.The students were exposed to 24 h of Turkish every week.They were taught grammar and the four language skills in these lessons.The researcher decided to choose participants from the most successful students according to their last proficiency exam results, because insufficient vocabulary can prevent L2 readers from constructing enough contexts to guess the meanings of unknown words (Laufer, 1997).

Participants
The participants were 14 intermediate level students.Since four of the students participated in the pilot study, they were not included in the main study, so the main study was conducted with ten students.Participants (6 females, 4 males) voluntarily participated in this study.They represented five different language backgrounds, including, Farsi, Arabic, Turkmen, Tajik and Swahili language.

Instruments
This was a fully qualitative study.A pre-test and a reading passage were the instruments used to collect data in this study.The researcher checked the pre-test about the affixes and the results revealed that many of the participants did well on the pre-test.In addition, a checklist was used just after each interview with each No. Derivational affixes 1 -cı, -ci, -cu, -cü, -çı, -çi, -çu, -çü 2 -gı, -gi, -gu, -gü, -kı, -ki, -ku, -kü 3.
-lstudent to check whether they were aware of the affixes which appeared in the target words.The passage chosen contained 236 words, 10 of which were target words that the researcher used to focus on the use of affixes in guessing strategies.
The target words included derivational affixes and they were all content words.The target words included three adjectives, four nouns, and three verbs.Instead of real words, plausible non-words, to which affixes were attached, were used as target words in the text in order to prevent students' possible familiarity with the words.Table 1 illustrates the derivational affixes in the target words.
Four suffixes that attach to nominal to form nominal, two suffixes that attach to nominal to form verbs, three suffixes that attach to verbs to form nominal and one suffix that attach to verb to form verb were provided in order to have many opportunities to collect data from the participants.The target words were italicized in order for participants to recognize them easily.The reading passage was adapted by Turkish language experts.The reading passage was intended to be lower than the students' actual proficiency level in order for the participants to understand it better and make successful guesses of the meaning of unknown words in the text.The researcher had three Turkish language teachers check the appropriateness of the reading passage in terms of its reading level.Little modifications have been done according to the reviews of those experts.To further check, the researcher piloted the same text with four students assumed to be similar to the participants in the main study with respect to language proficiency and level of reading comprehension.The students were asked to attempt to guess the meanings of the italicized words.Another purpose of the pilot study was also to check whether the students understood the text well.The researcher asked the students participating in the pilot study to read the reading passage out loud to check whether they understood the text.

Data analysis
This study included qualitative data.Qualitative data were gathered from transcripts of the tape-recordings and the researcher's notes taken during the think aloud protocols.Then, the researcher transcribed the tape-recordings and the data analysis was carried out on the Turkish transcripts.
Data analysis involved readings and re-readings of the transcripts by the researcher in order to code the types of knowledge sources used by the participants during the think aloud procedure.For coding categories, the researcher consulted the literature on vocabulary learning and lexical inference strategies (Paribakht, 1997;Nassaji, 2003).Moreover, the coding scheme the researcher used derived mainly from the data and reflected the thinking of the learners participating in the study.The researcher identified a total of four knowledge sources including grammatical knowledge, discourse/text knowledge, morphological knowledge, and world knowledge.
In addition to that, a second rater, who is an experienced Turkish language teacher and also a native speaker of Turkish, also identified and classified the knowledge sources.Grammatical knowledge was defined as using knowledge of grammatical functions or syntactic categories.Discourse/text knowledge was defined as using knowledge about the relationships between sentences or within sentences.Morphological knowledge involved using knowledge of word formation and word structure.World knowledge has two definitions in the literature: Nassaji (2003) defines it as the general knowledge about the topic and content that goes beyond what is in the text, but Paribakht and Wesche (1999) define world knowledge as learner familiarity with the theme and topic of the text.The researcher decided to use Nassaji's (2003) definition of world knowledge because his definition is much broader and more appropriate for this study.
To determine the degree to which participants were successful in inferencing the target words, the researcher and the second rater rated participants' responses to each of the unknown words in the reading passage.Successful inferencing was defined as responses that were semantically and contextually appropriate, whereas unsuccessful guesses were not accurate responses semantically or contextually (Nassaji, 2003).
After determining successful and unsuccessful responses, the researcher counted both successful and unsuccessful guesses, classified the knowledge sources, calculated the percentages, and classified each participant's responses to each italicized word he or she attempted to guess the meaning of from the context.
A think aloud technique was conducted to gather data from the participant students.The researcher met each participant in a quiet room for approximately 15 min to conduct the think aloud procedure.The participant students were asked to read a reading passage and try to infer the meanings of the 10 target words in the text.In addition, they were told to verbalize their thoughts while making inferences.The students were tape-recorded as the researcher conducted the think aloud procedure.Later, the taperecordings were transcribed and examined in order to reveal the data.
The researcher extracted and formulated the following information: (a) identification of the words learners guessed successfully or failed to guess successfully; (b) identification of the knowledge sources the participants used in order to guess the meanings of the target words.Each participant was expected to infer the meanings of each of these words, making a total of 100 attempts to infer meaning from context; however, after examination of the transcripts, target words were ignored on 9 occasions.Thus, the number of attempts was reduced from 100 to 91, for which responses could be interpreted as inference of an unknown word.

OVERALL RESULTS
Table 2 shows that of the total 100 opportunities to guess from context, 62 (62.0%) were successful.Twenty-nine (29%) were unsuccessful.In addition, the researcher identified 9 ignored words whose meanings the participants did not attempt to infer in anyway.If both unsuccessful and ignored words are considered together, students were unable to infer the meanings of 38 (38.0%) words.
Table 3 summarizes the students' responses to the unknown words in the reading passage.The reading passage included 10 plausible non-words (PNWs) which Yılmaz 679 were used in order to prevent students' possible familiarity with the words.Some of the participants gave no response to some of the target words.Accordingly, the data analysis is based on 91 responses provided from the participants.With regard to an item-by-item analysis of the individual words, the results demonstrate a wide variety of differences in students' responses to each of the individual words.For example, all of the students successfully inferred the meaning of the target words tulakçı (sanitarian) and eneldi (diminished).On the other hand, 7 participants could not guess correctly the meaning of ferimsiz.
Knowledge sources are what the learner refers to, such as world, morphological or text knowledge, when attempting to infer the meanings of unknown words (Nassaji, 2003).The analysis of the think aloud protocols showed that different categories of knowledge sources were used both successfully and unsuccessfully by the participants.Knowledge sources used included world knowledge, morphological knowledge, discourse/text knowledge, and grammatical knowledge.Sometimes the students referred to more than one knowledge source while guessing the meaning of a word.
Table 4 demonstrates the students' use of all knowledge sources when guessing the meanings of unknown words.Among the knowledge sources used by the participants, discourse/Text knowledge had the highest percentage (52.0%)and grammatical knowledge had the lowest (0.0%).
Table 5 illustrates the use of each suffix when the participant students attempt to guess the meanings of unknown words.Of all the Turkish morphemes appearing within the target words, the students never refer to two of the affixes: (-la,-le) and ( -sız, -siz, -suz, -süz).The students may not have been aware of these morphemes within the target words.On the other hand, (-cı, -ci, -cu,cü, -çı, -çi, -çu, -çü) and (-ca, -ce, -ça, -çe) were the most frequently used suffix by the students in their attempts to infer the meanings of the unknown words.
In the following section, some examples of the participants' attempts to use affixes in guessing the meanings of the unknown words are given.
Knowledge source: Morphological knowledge (-sız, -siz,suz, -süz) "…without prescription ferimsiz drug consumption…[…without prescription insensible drug consumption.-sizsuffix that attach to nominal to form negative nominal]" The data gathered from the think aloud protocols revealed that not all of the participants used Turkish morphology as a knowledge source when inferring the meaning of the target words in the context.Participants never referred to -la, -le suffixes in their attempts to guess the meanings of the unknown words.
(-sız, -siz, -suz, -süz), (-lı, -li, -lu, -lü), (-gı, -gi, -gu,gü, -kı, -ki, -ku, -kü), (-n) and (-l) suffixes have been used once in students' attempts to guess the meaning of unknown words.Participant 1 was the most successful in terms of morphology use as a knowledge source.She referred to affixes five times in total and five of these were associated with correct guesses.Some examples of the participants' attempts to use knowledge sources in guessing the meanings of the unknown words are given here.
Knowledge source: Discourse/Text knowledge "…eller su ile güzelce yuvandı ancak….[ …the hands were yuvandı (washed) but…yuvandı might be washed because in this sentences I see hands so hands are related with washing]" "…eller su ile güzelce yuvandı ancak….[…the hands were yuvandı (washed) but…yuvandı might be washed because in this sentence I see water so water is related with washing]" "…eğitim görmüş tulakçı tarafından …. beslenme…[ …by an educated tulakçı(sanitarian)……nutrition… tulakçı might be sanitarian, or a profession related with health, so the participant used both Discourse/Text knowledge and World knowledge]" "…eğitim görmüş tulakçı tarafından …. beslenme…[ …by an educated tulakçı(sanitarian)……nutrition… tulakçı might be medical student, or doctor, or a profession related with health, so the participant used both Discourse/Text knowledge and World knowledge]" "…sağlıklı yaşama kuralları hakkında sengi verilir.[ …sengi (information) will be given about sanitary living condition so, sengi might be information, because sengiverilir (giving information) is used together, I understand this because I know what verilir (giving) means]" Knowledge source: World knowledge "…konuşmalar yabancı dillerde ve Tengçe… [ …the speech was given in foreign languages and in Tengçe so, Tengçe might be a language, because an expert will give a speech in foreign language or any other language so as far as I remember this might be a kind of language like Turkçe (Turkish), Almanca (German), Arapça (Arabic)….]""…konuşmalar yabancı dillerde ve Tengçe…[ …the speech was given in foreign languages and in Tengçe so, Tengçe might be a language, because I see the the word foreign language so the doctors give speech in any languages]" "…son yıllarda bilinçli ilaç kullanmama miktarı ve sayısı eneldi[ …in recent years the drug usage has been eneldi(diminished) so, eneldi might be diminished, because an recent years people are conscious about the drawbacks of drugs, people tend to use herbs for health]" "…son yıllarda bilinçli ilac kullanmama miktarı ve sayısı eneldi[ …in recent years the drug usage has been eneldi(diminished) so, eneldi might be increased, people try to use various drugs because of the developments in medicine, drugs are cheap and easily accessible]" "…sağlıklı yaşama kuralları hakkında sengi verilir.[ …sengi (information) will be given about sanitary living condition so, sengi might be information, because doctors usually gives information about sanitary living conditions]" In this study three Turkmen students use L1 knowledge source, "…eller su ile güzelce yuvandı ancak….[ …the hands were yuvandı (washed) but…yuvandı might be washed because in my native language (Turkmen) yuvamak means to wash, which sound similar to madeup word yuvandı.

DISCUSSION
This study investigated the use of Turkish derivational affixes and knowledge sources by Turkish as foreign language learners in inferring the meanings of unknown words encountered in written contexts.This section will answer the research questions of this study and discuss the findings in the light of the relevant literature.
1. To what extent do Turkish language learners refer to Turkish derivational affixes in order to guess the meaning of an unknown word in written contexts?
Yılmaz 681 This research question was answered by looking at the participants' behaviors using Turkish affixes when attempting to guess the meanings of the target words encountered in the reading passage.According to the result of the study foreign students are not successful in referring to affixes while guessing the meaning of unknown words.Paribakht (2005) stated that there is a clear relationship between vocabulary knowledge and successful inferencing.So, individual differences in terms of vocabulary knowledge might have taken a role in their use of suffixes, or some participants might have not been aware of the affixes.Nagy and Anderson (1984) also stated that morphemic awareness might be regarded as an analytic skill, which some of the participants may lack.Another reason that Turkish as a Foreign Language Learners did not often refer to Turkish morphology as a knowledge source might be the morphology of Turkish language.Turkish is an agglutinative language.Agglutination refers to the process of adding suffixes to a root-word, thus transforming a single word into a phrase or a complete sentence depending on the chain of suffixes attached (Kurtoğlu-Hotoon, 1995,p.20).Crystal (1991, p.19) stated that different languages display the characteristics of agglutination in different degrees and gives Turkish as an example of a language that largely displays agglutination.Agglutination in Turkish is due to the wide use of suffixes.These are affixed to root words to form nouns, adjectives, and verbs.It is not possible to teach all the affixes to the Turkish as foreign learners.In this study most frequently used affixes are (-cı, -ci, -cu,cü, -çı, -çi, -çu, -çü) and (-ca, -ce, -ça, -çe) by the students in their attempts to infer the meanings of the unknown words.The reason might be that the teachers might have emphasized these affixes more in the class activities.
2. Which knowledge sources have been used in guessing the meaning of unknown words?
This study showed that different categories of knowledge sources were used both successfully and unsuccessfully by the participants.Knowledge sources used included world knowledge, morphological knowledge, discourse/text knowledge, and grammatical knowledge.Sometimes the students referred to more than one knowledge source while guessing the meaning of a word.Among the knowledge sources used by the participants, Discourse/Text knowledge had the highest percentage (52.0%)and grammatical knowledge had the lowest (0.0%).World knowledge is "using knowledge of the content or the topic that goes beyond what is in the text" and Discourse/Text knowledge is "using knowledge about the relation between or within sentences and the devices that make connections between the different parts of the text" (Nassaji, 2003, p.656).In this study most of the students who use World knowledge used the Discourse/Text knowledge as well.Knowledge sources used by the participants, Discourse/Text knowledge (52.0%) and World knowledge (31.8%) had the highest percentages.

Conclusion
The results of this research revealed that Turkish language learners used a variety of knowledge sources in the process of inferencing vocabulary meaning during L2 reading, such as World knowledge, Morphological knowledge, Discourse/Text knowledge, and Grammatical knowledge.In addition, Turkish language learners made frequent erroneous guesses, and on some occasions made no guesses at all.Turkish language learners did not use grammatical knowledge, which may indicate that information about the grammatical function of the words may not help students in their attempts to infer the meanings of unfamiliar words in context (Nassaji, 2003).
The research revealed that the participants as a whole appeared to be unsuccessful referring to affixes in many of their attempts to deduce the meanings of unknown words.Thus, even though Turkish language learners appeared to experience some success in referring to affixes in their attempts to unlock the meanings of unknown words, they did not often refer to suffixes when reading.Turkish language learners did not often refer to Turkish morphology as a knowledge source might be the morphology of Turkish language.Turkish is an agglutinative language and largely displays agglutination.
Another reason that learners did not often refer to Turkish morphology as a knowledge source might be that they do not read a lot in the target language.There is a relationship between reading and morphological awareness.For example, the person who does not read very much probably will not be able to see the contribution of the affix -cı, -ci, -cu, -cü, -çı, -çi, -çu, -çü to the meaning of a person practicing a certain profession, or having a certain occupation: koruyucu 'guardian', öğrenci 'student', dilenci 'beggar'.
Another reason that the use of affixes is not very high in inferring the meanings of target words in written context may be that the target words are not real words.The participants might have recognized and used the affixes more frequently if real words had been used instead of made-up words, because the participants might have recognized the bound stems and they could decide what part of the target word is an affix.When Turkish language learners encounter an unfamiliar word while reading, they often infer its meaning using available information and knowledge (Discourse/Text) not using Morphological knowledge for guessing the meaning of unknown words.And also grammatical function of the words did not help students in their attempts to infer the meanings of unfamiliar words in context.

Implication for Further Studies
Taking the limitations of the study into consideration, a similar study should be conducted with students from different levels, because language proficiency is influential in analyzing unfamiliar words.In addition, in order to reveal the successful use of affixes as a knowledge source in guessing the meanings of unknown words, a similar study may be conducted with students who have been provided with instruction in guessing strategies and Turkish morphology.Furthermore, a further study may be conducted with more students, in order to reveal more accurate results.In addition, different texts at different difficulty levels and different genres might be used for such studies.

Table 1 .
Derivational affixes in the target words.

Table 3 .
Successful and unsuccessful inferences for unknown words.

Table 4 .
Students' use of knowledge sources.

Table 5 .
The use of each suffix.