lexical and grammatical cohesive ties on elementary, intermediate, and advanced iranian english language university students in argumentative and expository writings

as far as the communicative essence of writing is important, cohesion is attended as a basic textual part both in developing organized texts and presenting the content realizable to the reader. many scholars have sought the relation between the use of cohesive devices (cds) and the students’ proficiency level. to obtain more comprehension into this scope, this study reviewed some studies centralizing the use of cds and the connection between the number of cds and the students’ proficiency level in argumentative and expository writings. the resolution of obtained data from several scholars of efl/esl has exhibited that there is somewhat connection between proficiency levels of students and the extent of using cds in their writings. the aim of the current research is to study the amount of cds used in argumentative and expository genres of writing constructed by university students and the relationship between the extent of using cds and students’ proficiency levels. the participants were native speakers of farsi between 23 to 26 years old, studying english as a foreign language in universities of ilam, ahvaz, and yasuj, iran. the sample contained 18 male and 18 female students. they were asked to perform the oxford placement test (opt) in the first session and after a week they are asked to compose either argumentative or expository writing. the results displayed that the university students use more cds in argumentative writings compared to expository writings. likewise, the findings of the study have illustrated that the proficiency level has had a significant role in the extent of using cds. that is, advanced students used more cds in their writings compared to intermediate and elementary students and intermediate students have used more cds in their writings that that of elementary students.