Analyzing the grammatical and non-grammatical phenomena in the written discourse of university students corresponds to the foundation of this article. For this, the mixed type of research with a descriptive design is considered, integrated with two methodologies from applied linguistics, corpus linguistics (LC) and error analysis (AE) proposed by Ferreira Tunner (2014). The intervention subjects were made up of thirty-six (36) university students who took the Language and Communication course for the year 2020, Faculty of Humanities, Department of Spanish, University of Panama. The data collection technique and instrument, the survey and an open questionnaire were administered and sent through a Google form containing three (3) sections. Section 1 presented the project summary and informed consent; section 2 corresponded to the description of the student's profile and section 3 indicated the practical part of writing developing three types of texts: descriptive, narrative and argumentative. As final considerations, the presence of grammatical and non-grammatical phenomena generated identified from inappropriate morphosyntactic use in articles, pronouns, verb forms, prepositions, and sentence structure is raised.