This study explores integration and linguistic acculturation in Catalonia (Spain), a multilingual setting where a state and a regional language coexist with those of immigration. Using qualitative content analysis, we examined the linguistic acculturation profiles of 13 high-school students of immigrant background and the linguistic acculturation expectations of 15 autochthonous students, considering Spanish, Catalan and heritage languages. Then, we explored their understanding of what integration means and its relation to language. Public use of heritage languages was the main source of friction. Participants of immigrant origin with assimilation profiles only used heritage languages with family, while those in multilingual profiles also used them in the public domain. Autochthonous students condemned their use in public, although they supported their use at home. Students from immigrant backgrounds advocated for a more inclusive understanding of integration, particularly those in multilingual profiles, but autochthonous students equated integration to assimilation. Educational implications are discussed.