In this article, Josiane Boutet, Pierre Fiala and Jenny Simonin-Grumbach offer a response to the erstwhile dominance in sociolinguistics of the “covariance” thesis of language and social structure as distinct domains. Introducing the notion of language practices, the article emphasizes the reciprocal and co-constructive role of language as social practice. They present the notion that language practices are both regulated and produced by the social, while at the same time, they act upon and can transform the social order. In other words, the social is shaped by language, and language shapes the social. Drawing on an example from the terrain of language and work, the article offers a conceptualisation of language as a constitutive element of social formation, and not merely an object that bears the traces of a social to be located somewhere outside of language.