Catalan is an autochthonous minority language within the Spanish state that is undergoing a programme of linguistic normalisation which is widely regarded as a successful model. Today, its progress is being challenged by globalisation, mass migration, and the sociolinguistic agencies of new migrants, in particular Spanishspeaking Latin Americans, who are allochthonous speakers of marked varieties of the official language of the Spanish state. The micro-level focus of the study is on how Spanish-speaking Latin Americans are constructing Catalan: how Catalan is being incorporated into repertoire (in-group and inter-group), and how and why individuals are forming conflicting constructions of being addressed in Catalan. At the macro level, the focus is on how policies of linguistic normalisation of the Catalan language are responding to the challenges of globalisation, and to the sociolinguistic agencies of new migrants, especially Spanishspeakers. Semi-structured interviews were carried out with 44 informants, and recordings made of the interactions of 11 of them. The focus of the data collection was on [i] Spanish-speaking Latin Americans' interactions involving Catalan, [ii] on the paths of migration and of identity formation along which individuals' epistemologies evolve, consolidate and transform, and [iii] on informants' opinions about language policies. The study is framed around 'structure and agency' (Giddens, 1984), and the data analysed according to a view of language as recursive social practice, which links the macro and the micro, seeing individuals' agencies as the outcomes of social structures and also as engendering change in these structures. Central to individuals' recursive language practice is knowledgeability and reflexivity (Giddens, 1984) as they interact in a heteroglossic Catalonia (Pujolar, 2001), and negotiate codeswitching norms of practice that are specific to Catalonia, in particular an 'accommodation norm' (Woolard, 1989) which involves Catalan speakers often switching to Castilian with interlocutors who do not look or sound Catalan.