The article describes the legal configuration of France as a monolingual state and analyzes the specific case of the educational system. A certain accommodation of regional languages as a means of instruction has been accomplished, either in time-parity bilingual sections or in immersion schools. In this respect, the data provided by the literature on the case of Catalan in the historic territory of Roussillon are reviewed. The sources analyzed show two main conclusions: (1) the breakdown of intergenerational transmission, which means that there are practically no dialect speakers and that the standard language can only be learned at school; and (2) the enrollment rate either in time-parity bilingual sections or immersion schools is too low to be able to reverse language shift.