Writing in the first language can be a challenging task. Indeed, it is even more challenging to write in a foreign language since the focus of writing is not only on the content but also on the form of the target language. In composing a good paragraph, discourse markers (henceforth DMs) is employed to make the sentences stick together supporting the topic sentence. To adopt the taxonomies of Halliday and Hasan (1976) and Halliday & Mattiessen (2004) to account for the semantic functions of DMs, this study was aimed to investigate what kinds of DMs employed by Indonesian and Thai students in their argumentative composition. Also, this study is aimed to compare and contrast the use of DMs by both groups in terms of its nature and problems. The subjects of the study were 46 pieces of argumentative composition produced by EFL university students. The data were analyzed quantitatively and qualitatively. The findings revealed that there were yielded high varieties of DMs employed by EFL Indonesian and Thai university students. In addition, the similarities and differences were also drawn related to the causes and problems occur. The paper was concluded with some recommendations and suggestions that should inform EFL writing instruction in this part of the world and in other similar context.

Keywords: discourse markers, cohesion, argumentative composition, EFL university students