The theme of this paper is the relationship of language ideologies as they may be uncovered in public discourse and as they are mediated through language users, for instance in minority families, to linguistic practices as observed among young speakers in a superdiverse environment in Copenhagen. We build on data from the Amager Project, a longitudinal study of the development of polylanguaging among adolescents, and analyze both explicit statements about language norms and observed and recorded language practices. We find that the young speakers encounter different norms for language use in their everyday life and that they themselves have a quite sophisticated sense of variation, both in their explicit statements on language use and in their actual behavior we can observe.