The issue of the use the use of French language in Africa has always fueled scientific and academic research. The present reflexion questions about the recurrence and perpetuity of syntactic "mistakes" of "3ème" students in writing, although they learn grammar rules since primary school classes. This logic appears to be a fact which merits attentions because of the norm taught by public power and teachers who did not take in consideration some sociolinguistics context. The notion of socioculture considered as prism in the writing process of student has some influences on these processes we can qualify as "indigenous". Written expression is always considered though as correct, pure, logic, and normalized. Our corpus in this survey show this language is different from French. Writing practices of the students is proving it. Some grammatical confusions and generalization have been record in student's essays. This article envisions describing, analyzing and understanding the perpetual accordance mistakes in written French by students of this class compared to the normative form.