One of the challenges in ESP classrooms is teaching writing genres, especially to students who come from fields that are taught in L1. This is presumably “not only because different languages seem to have different ways of organizing ideas and structuring arguments but because students’ prior writing experiences in the home, school or elsewhere do not prepare them for the literacy expectations of their university or professional workplace” (Hyland, 2013, p. 95). In our study, we analyze 36 argumentative essays written by students of Political Science and International Relations in an English for Social Sciences course taught at the West University of Timisoara in Romania. The essays are written in English and the students’ L1 is Romanian. The aim of the study is to find out to what extent argumentative structures in English are influenced by Romanian academic writing genre norms. For our analysis, we use corpus linguistics methods, looking at frequencies and phraseology patterns as well as prominent rhetoric features related to argumentation. We argue that translations of Romanian structures feature prominently when descriptive moves (description, definition, enumeration) are employed.