This article attempts to describe the most frequent types of errors French-speaking university students commit when they produce and revise a text, as well as the types of strategies leading to their errors. Twenty-four first-year university students were asked to produce metagraphic comments, i.e., to verbalise their thought processes, during revision and production. More errors are left in the text to revise than in the text to produce. The most frequent error in both tasks is syntax; to those mistakes are added sequence of tenses and vocabulary problems in revision, grammatical agreement, and spelling in production of text. Errors are often left without arousing a problem solving strategy, especially in revision. The most common strategy that leads to errors is the use of a metalinguistic procedure that shows incorrect or insufficient knowledge. Students’ strategies vary according to the type of problem at stake. Their linguistic competence predicts the number of errors remaining in the text produced but not in the revised text; it predicts poorly the type of strategies that are chosen. Those results suggest that students’ linguistic problems seem to be mainly due to a lack of knowledge rather than to problems in accessing that knowledge. The study therefore emphasises the importance of structured work on language till the university level.