Discourse is essential in communicating thoughts and ideas. People around the world communicate their ideas through stretches of language. In order to understand any discourse, it must achieve cohesion. The purpose of this paper is to define and describe the cohesive devices based on the work of Halliday and Hasan (1976). It also aims to emphasize the necessity of using these devices by analyzing a Michigan English Language Assessment Battery (MELAB) sample examination of a student's essay writing. The student's writing shows clear evidence of cohesion and demonstrates the use of grammatical and lexical devices. It is noticed that the most grammatical devices used are reference and conjunction. On the contrary, there is little evidence of using lexical devices. Although the essay is somewhat cohesive, some areas still need improvement.