Following these previous studies, this present research aims to
investigate cohesive devices used in students‘ essays and to compare which
subtypes of cohesive devices are the most prominent among three groups of
students. In consequence, cohesion is a significant common issue in written
language and pedagogy. It is an indispensable tool for not only writers to
improve their writing skill and guarantee their writing maturity but also for
language teachers to prepare practical writing courses and to provide some
useful guidelines when responding to students‘ written work.