This article examines the consequences of the appropriation of sociolinguistic concepts by teachers participating in a pilot educational program. It will shed light on the problems caused by the disparity between, on the one hand the representation of the sociolinguistic situation of Reunion Island based on the model of diglossia and, on the other hand, the real practices of speakers which reflect an interlectal mode of communication. These problems will be discussed and illustrated through the empirical data selected from our corpora.