Learning and its internal processes depend on the institution of a socio-discursive space for sharing meanings. The inclusion of students in the social universe constituted by the discipline of French depends on a psychological instrument deployed mainly in the classroom by teachers: language. Considered as a founding instrument of the teacher’s work, language as a professional didactic linguistic gesture fosters continuity and unevenness in the elaboration of knowledge by pupils, and aims to transform, through linguistic negotiations and readjustments, their spontaneous language use to bring them into a field of unfamiliar practices, values and content. However, the adoption of a horizontal register with regard to pupils seen as having difficulties increases inequalities at school. Interest in the relationship between language and the construction of knowledge is evident from the upsurge in research into language activity in the classroom. We propose a conceptual reformulation that sheds light on the links between language and the formation of social and cognitive actors who (re) construct semiotic systems specific to the learning of French, and who acculturate to the ways of saying, thinking and acting of the discipline in question.