The present research analyzed the codes of marks as a technique for the correction of errors in the written expression of the French language of eighth semester students of the Plurilingual Career of the Universidad Central del Ecuador. The research has a qualitative approach, since it describes the problem in order to reach an understanding of it. Therefore, two instruments were applied: The checklist and the rubric through which the necessary data were collected to know how the mark codes are used and what is the level of mastery of written expression of the French language. In addition, the bibliographic and field modality was used. That is to say, for the research process we resorted to the analysis of bibliographic sources in order to know the different perspectives of the authors on the subject, and for the gathering of evidence, observations were made in the place where the problem was presented. Once the analysis and interpretation of the results were carried out, it was concluded that the marking codes are used by the teacher in most of the corrections made in the students' writing tasks.