This paper examines the preferred patterns of argument development in argumentative essays written by a group of advanced Arabic-speaking learners of English as a foreign language. To this end, the text structure of 104 essays written by 52 Master students is analyzed building upon the model elaborated by Hatim (1990, 1991, 1997). The results show that the student writers, influenced by their native culture’s writing conventions, follow predominantly the pattern of through-argumentation to construct their argument. On the other hand, some of their observed argumentative discourse deviant forms are not explicable in the light of transfer factors. The implication of the study is that multiple factors come into play when the discourse conventions of English argumentative writing are distorted in EFL learners’ texts. We recommend that for the teaching of written argument to be efficient, lecturers adopt instruction in which exposure to the argumentative essay genre is highlighted while activating student writers’ potentials of revision and self-editing.