THE CONTRIBUTION OF LEXICAL COHESION TO THE TEXT COHESION IN EFL STUDENTS ’ EXPOSITORY TEXTS

Writing is one of the major language skills that the students should master. This skill also employs the students to manifest their thoughts and ideas in an authentic and permanent form. In other words, writing is a process where students, as the writers, explore thoughts and ideas, and make them visible and concrete. Furthermore, it encourages thinking and learning, motivates communication, and makes thought available for reflection.


INTRODUCTION
Writing is one of the major language skills that the students should master.This skill also employs the students to manifest their thoughts and ideas in an authentic and permanent form.In other words, writing is a process where students, as the writers, explore thoughts and ideas, and make them visible and concrete.Furthermore, it encourages thinking and learning, motivates communication, and makes thought available for reflection.
In expressing ideas in writing, students should be encouraged to ensure that their text flows through the sequence of sentences.Thus, it is crucial to guide them to the thoughts and ideas they wish to express, as well as the sentences they use to express those ideas (Holloway, 1981).In order to make the sentences readable, they should be connected to each other.It is because a good text is not determined by its length but it depends on its connectedness and its unity (Brostoff, 1981;But et al, 2006).
A text can either be written or spoken (Halliday and Hasan, 1976;Matthiessen, 2004;Butt et al., 2006).A text is defined as a complete linguistic interaction from beginning to end as a reflection of any instance of language that makes sense to someone who knows the language (Eggins, 1994;Halliday and Matthiessen, 2004).In other words, what is important in a text is not its length or medium but its meaning or sense that can be identified and comprehended by the readers or receivers.It is also relevant with Halliday and Hasan (1976) as cited in Eggins (2004) that a text is best regarded as a semantic unit, a unit not of form but of meaning.Furthermore, the text should have texture that makes words 'hang together' or become fixed meaningfully in a unity of text (Halliday and Hasan, 1976).It is also in line with Eggins (2004) that texture is 12 referred to the interaction of two components called coherence and cohesion.Therefore, to be a text, those minimum units of meaning should be related in a coherent and cohesive way.The coherence of the text is determined by the connection between its social and cultural contents while on the other hand cohesion is the way the element of the text are bound together as a whole.In other words, a text is a passage that becomes meaningful because coherence and cohesion are intertwined to create a text as a whole.Texture will help readers to understand the semantic relation of the text.Hence, writers' knowledge of semantic relation will determine readers' comprehension to the text or passage.
According to Halliday and Hasan (1976), cohesion is regarded as one of the fundamental elements of texture to determine the connectedness and unity of sentences in a text.It is important for the students to join ideas between sentences to create texture (Halliday and Hasan, 1976).Cohesion is defined by Halliday (1994) as one of the essential elements of texture stated as non-structured resource for discourse to hold the text together and give the text a meaning.Cohesive devices provide a text to preserve consistency and connectedness throughout a text or passage.They are texts-specific linguistic elements used to associate an integrated, interpretable, and meaningful text.Cohesion is realized through cohesive devices i.e. reference, ellipsis, substitution, conjunction, and lexical cohesion (Halliday and Hasan, 1976).These domains are intertwined together and their proper existence will enable the readers to understand the text or passage.
Cohesive devices, according to Halliday and Hasan (1989) as cited in Hoey (1991), separate cohesive devices into five domains i.e. reference, substitution, ellipsis, conjunction, and lexical cohesion.They are defined as non-structural resources employed in the surface structure of the texts.The models of cohesion proposed by Halliday and Hasan (1976) are obvious between sentence as those within the sentences that can also be a function as structural elements.In addition, Halliday and Hasan (1989) define cohesion as a semantic relation between elements in the text and some other elements that are fundamental to its interpretation.McCabe (1998) delineates cohesion as a term taken from Latin word 'coheasio' meaning cling together.In other words, he puts an emphasis that language forms are used to indicate semantic relations between elements in a discourse.On the other hand, Butler (1985) defines cohesion as belonging to the system of language.It is not something, which is merely, arising from outside.Instead, it is concerned merely with the subject matter of text.Moreover, Cook (1992) confirms the theories from Halliday and Hasan (1989) and Butler (1985) that cohesion is a nonstructural resources employed to create a text or passage.He points out to the cohesive devices as formal links to create relationship between sentences and clause.These devices or domains enable the writers to conduct a text in a whole and be more readable as a unity.
Furthermore, it is inferred by Paltridge (2006) that cohesion is defined as a relationship between items (cohesive devices) in a text such as words, phrases, clauses, and any other items such as pronouns, nouns, and conjunctions.It is also in line with Botley and McEnery (1996) that a text is considered as a cohesive one if the sentences and spoken utterances are semantically linked in a consistent way.The text will be less effective if the readers are not able to identify and recognize the connection of the sentences and spoken utterances.
Cohesion, thus, is realized through cohesive devices which can be identified within or across the sentences.It is also relevant with Halliday and Hasan (1976) that classify cohesive devices into five ELT in Focus, Vol.1(1) June 2018 Copyright © 2018 ELT in Focus 13 major categories i.e. reference, substitution, ellipsis, conjunction, and lexical cohesion.Moreover, Halliday and Hasan (1976) delineate cohesion as a semantic concept which is mainly realized through the existence of two types of cohesive categories namely grammatical and lexical cohesion.Grammatical cohesion is realized through reference, substitution, ellipsis, and conjunction.Meanwhile, lexical cohesion is achieved through reiteration and collocation.

Lexical Cohesion
Lexical cohesion is realized by repeating the same lexeme or general nouns.In other words lexical cohesion involves the repetition of a noun phrase or the use of another noun phrase which stands a relation to the antecedent noun phrase (Gutwinski, 1976;Halliday and Hasan, 1976;Beaugrande and Dressler, 1981;McCarthy, 1991;Hung and Thu, 2014).Halliday and Hasan (1976) divide lexical cohesion into reiteration (which is subdivided into the repetition of a lexical item, the use of a general word to refer back to a lexical item, and the use of synonymy, or superordinate terms) and collocation.Lexical cohesion is a cohesive relation whose cohesive effect is realized by the selection of vocabulary.Baker & Ellece (2011: 69) define lexical cohesion as a way of achieving cohesion by repeating the same word or phrase or using chains of related words that contribute towards the continuity of lexical meaning.Another definition by Yeh (2004: 8) indicates that lexical cohesion is an openended and a less adequate defined cohesive means that differs from other devices in being not bond with any special group of items.Chan, T'Sou, Choy, 2000) also assert that constant repetition of lexical items would make easier for any readers to match strings in a sequence of sentences.In other words, lexical cohesion plays an important role to make readers comprehending a text or a passage in a whole.
In addition, Kunz, Maksymaski, and Steiner (2009) state that lexical cohesion is not limited to link only two items like other categories.In other words, it serves to create cohesive bonds between two or more referring expressions by means of lexis.A lexical element in that anaphor makes a semantic connection to an item within the antecedent.
Repetition refers to words that are repeated in a text.It can be seen from the example below.The word 'bear' used in the first sentence is repeated as the realization of the repetition.
Algy met a bear.The bear was bulgy.(Halliday, 1994: 330) Synonym refers to words which are similar in meaning.In this example, there are two kinds of synonyms.First, the word 'block' has the same meaning with the word 'men' in the subsequent sentence.On the other hand, the word 'women' in the first sentence has the same meaning with the word 'girl' in the subsequent sentence.It can be seen in the example below.

I'm just none of those blokes that finds approaching women easy.
The book assumes all men are confident, or that if they really like a girl, they'll overcome their shyness.The opposite is true.(Cooper, 2005: 38) Antonym refers to opposite meaning or contrastive meaning.It can be proven in the example below.In this passage, the noun phrase 'real players' has the opposite meaning with the noun phrase 'boofheads'.
Only real players do full-on charm.The rest of us are boofheads.(Cooper, 2005: 38) According to Halliday (1994), hyponymy is one of the subclasses of synonym which indicates a relation of specific-general.In other words, it can be described that hyponymy refers to the classes of lexical items where the relationship between them is one of "general-specific.It can be identified in example #14 taken from Rydin (2002).In this example, the hyponymy is represented by word "cars" as general noun.Then, the word "cars" is specified into 'Volvo', 'Neat', and 'Ford'.
"Such cars as Volvo, Neat, and Ford…" (Rydin, 2002) Meronymy is also one of subclasses of synonym refers to a part-whole relation (Halliday, 1994).In other words, meronymy is where lexical items are in a "whole to part" relationship with each other.It can be viewed in example #15 taken from Corston-Oliver (2012).In this example, there are two chains of meronymy.The first one is: 'dog-teeth' and the second is: 'cat-tail'.
Your dog bit my cat on the tail with its sharp teeth.
(Corston-Oliver, 2012) Another type of lexical cohesion is collocation.Halliday & Hasan (1976: 287) use the notions of collocation and collocational cohesion as an umbrella term for the kind of cohesion produced by the cooccurrence of lexical elements that are in certain point or another typically linked with each other due to their identical context.
Furthermore, Halliday & Matthiessen (2004: 577) define collocation as a particular association between words based on their tendency to accompany each other.Most of time, collocations are linked with a certain kind of register or a function as a variety of language.Moreover, it is in line with Paltridge (2006: 137) that collocation describes associations between vocabulary items which have a tendency to co-occur.This type of lexical cohesion does not depend on any general semantic relationship like other previous types.For example: father-mother, doctor-patient, teacher-students, etc.In example #16 below taken from Halliday (1994: 333) will give more comprehensive understanding.According to this example, the collocation is marked through the use of words 'smoke' and 'pipe'.There is a strong relationship between 'smoke' and 'pipe'.A pipe refers to something you smoke.Therefore, pipe here can be assumed as the 'pipe he was smoking at that time.

A little fat man of Bombay Was smoking one very hot day But a bird called a snipe Flew away with his pipe
Which vexed the fat man of Bombay (Halliday, 1994: 333).
Research Questions: The present study aims to investigate the use and the contribution of lexical cohesion in students' expository texts.It involves the variety of lexical cohesion employed by the students to conduct a semantic relation; and to investigate the contribution of lexical cohesion to students' expository texts.This study uses the framework of cohesive devices proposed by Halliday and Hasan (1976).Therefore, this study attempts to answer the following research questions: 1) What types of lexical cohesion are found and identified in students' expository texts?2) How do the cohesive devices contribute to the cohesion of students' expository texts?

Source of data
The data in the present study were documents from nine students' expository texts.They were asked to write an essay in two hours.The instruction for students to write an exposition text is attached in Appendix.The authentic forms of the writing documents were the students' handwriting about the topic given in expository genre.The authenticity of the students' texts resulted the fundamental data in this study.Students' authentic texts were the data in this study to answer the research questions.

Procedure of data analysis
The data in form of students' expository texts were analysed by using theoretical frameworks proposed by Halliday and Hasan (1976) concerning the concept of cohesive devices analysis and Eggin's point of view (1994) regarding cohesive devices interpretation.In analysing the data, this study proposed several procedures.Firstly, each text was chunked based on clause.It was very important to conduct a careful analysis.It was because the data were in form of students' expository texts which consist of several paragraphs.Secondly, identification was initiated to mark the cohesive devices found and identified in the clause.In this procedure, the words were underlined and put to where they belong.Thirdly, classification was done to classify the underlined words and put to where they belong according to the frameworks proposed by Halliday and Hasan concerning cohesive devices i.e. reference, substitution, ellipsis, conjunction, and lexical cohesion.The last procedure was drawing a descriptive quantification.This procedure was crucial to calculate cohesive devices found and identified in students' expository texts.After the words were identified and classified, they were calculated and presented through the descriptive quantification.Moreover, it is beneficial to elaborate, enhance, and illustrate the results of the study.

Types of lexical cohesion identified in students' expository texts
This sub chapter presents the use of lexical cohesion in students' expository texts.The texts are analysed by using the concept of cohesive devices underlined by Halliday and Hasan (1976) which covers reiteration (i.e.antonymy, repetition, synonymy, meronymy, and hyponymy) and colocation.
The occurrence of lexical cohesion identified in nine students' expository texts can be seen through descriptive quantification as illustrated by Table 3.1 below: meronymy with 12 occurrences; and hyponymy with 13 occurrences.On the other hand, it is subsequently followed by the collocation with 25 occurrences.According to Table 3.1, it can be inferred that most students use reiteration to link their text as a unity.They only use some collocation items in their texts.It is because they are not aware enough of the use and the function of collocation.

The contribution of lexical cohesion to students' expository texts
This sub chapter provides the contribution of lexical cohesion found and identified in nine students' expository texts which involves reiteration (i.e.antonymy, repetition, synonymy, meronymy, and hyponymy) and colocation.The result of the study indicates that there are only two contributions of lexical cohesion to students' expository writing.The contribution of lexical cohesion in nine students' expository texts can be seen through the Table 2 below.According to the Table 2 as aforementioned, lexical cohesion occurs 179 times.It can be, in particular, stated that lexical cohesion provides contribution in keeping track of the participant.This contribution is realized by reiteration.It is, more specifically, realized by the occurrence of repetition with 154 occurrences.Keeping track of the participants is an attempt to help the readers to track referents in the text.The chains also helps the readers to identify whether the referents are coming from inside the text (internal entity) or outside the text (external entities).It is relevant with what Eggins (2004) says, "Participants are the people, place, and things that get talked about in the text."It is also relevant with Hasan (1976), Martin (1985), and Ventola (1987) that through chains of participant occurrences, the readers come to understand the roles these text participants play in the texts and come to treat the text as coherent unit.
Meanwhile, lexical cohesion also contributes in engaging the readers to the core argument of the text.This contribution is realized by the occurrence of reiteration, particularly repetition with 12 occurrences, and collocation with 25 occurrences.Engaging the readers to the core argument of the text assists the readers to recognize the core entity in the text.Therefore, it can be inferred that the occurrence of reiteration and collocation enable the readers to get engaged to the core argument of the text easily.

CONCLUSION
In line with the research questions as aforementioned, the purposes of this study are to identify the types of lexical cohesion in nine students' expository texts and investigate the contribution of lexical cohesion to students' expository texts according to the concept of cohesion proposed by Halliday and Hasan (1976).
Firstly, the students use various type of lexical cohesion.It can be seen from the occurrence of lexical cohesion employed by the students with total 322 occurrences.More specifically, they use reiteration i.e. repetition (154 occurrences), synonymy (24 occurrences), antonymy (2 occurrences), meronymy (12 occurrences), and hyponymy (13 occurrences).Moreover, they also employ collocation in their with 25 occurrences.However, although the use of lexical cohesion in their texts is considered high, it is still problematic since they mostly utilize improper lexical cohesion.As a consequence, their texts tend to be difficult to read and comprehend.
Secondly, the students mostly utilize lexical cohesion in keeping track of the participant.This contribution is realized by reiteration in particular repetition.On the other hand, students also use lexical cohesion in engaging the readers to the core argument of the text.This contribution is realized by collocation.
Nevertheless, the overuse of lexical cohesion by the students causes redundancy in their texts.As a result, their texts are difficult to comprehend.There is a tendency, instead of focusing on the relations of meaning that exist between the text, the students only put an emphasis on the word and sentence level.The result of this tendency is the absence of connectedness that enables readers to comprehend the text.Thus, the students should be encouraged to apply proper lexical cohesion as many as possible to make more cohesive text.Therefore, cohesion, in particular lexical cohesion, is very fundamental since it provides a sequence of sentence a coherent texture as it shows how semantic relations are constructed by lexical and syntactic features.Furthermore, by realizing the functions of cohesion, in particular lexical cohesion, will positively affect to EFL students to create meaning.It will also build a good communication between writer and readers.
Moreover, this study suggests that the use of cohesive devices, in particular lexical cohesion, should be taught explicitly.It will assist students to obtain more understanding and knowledge regarding the use of lexical cohesion.There is also a tendency where teaching methods concerning cohesive devices is only implemented in a small range.The present study suggests more effective strategies to present cohesive devices, in particular lexical cohesion, in English language teaching including the teaching methods in the larger unit of the discourse.Therefore, these efforts will assist EFL students to utilize proper cohesive devices in conducting more cohesive text in different genres.
For the further study, it is suggested to investigate the use of cohesive devices in different texts or genres i.e. argumentative, recount, etc.This study also suggests to analyse the coherence in students' texts since it mainly focuses on the use and the contribution of cohesive devices particularly lexical cohesion.Therefore, it will cover not only the contribution of cohesive devices but also the contribution of transitivity, mood, and thematic structure, and also context of culture.

Table 1 .
The occurrence of lexical cohesion

Table 2 .
The contribution of lexical cohesion to students' expository texts