Argumentation is a skill that promotes logical reasoning, as well as social participation and the development of citizenship. Therefore, it has become a relevant teaching tool in schools. For students, however, producing written arguments demands both high levels of cognition and linguistic skills. Few studies exist that have focused on students with these attributes. The purpose of this research is to explore the profiles of student writers with respect to the quality of their written arguments, as well as to establish the link between these profiles and students’ academic language resources (ALR). One hundred and twenty-six Chilean 8th graders from three schools were assigned an essay on the use of tablets in the classroom. The quality of their essays was assessed using a rubric to determine the mastery of their argumentative skills. In addition, academic language resources-academic vocabulary, nominalization, discursive markers, epistemic and deontic markers-were coded using CLAN. An analysis of latent classes (ACL) determined the profiles. A total of 69% of the students displayed attributes of the so-called “emergent” profile. The remainder belonged to the second profile, called “developing.” In these two categories, the use of ALR was analyzed. In the “emergent” profile, there are two classes of students who differ substantially in the use of nominalizations (by presence and/or absence) and cross-disciplinary academic vocabulary. The “emerging” profile also contains two types of students: some with a more homogeneous use of ALR, while others use cross-disciplinary academic vocabulary, nominalizations and deontic markers. The study concludes that students need more opportunities to learn how to build arguments and to deploy academic language resources in order to strengthen their points of view.