In the last decades, many elite schools, which were founded following national models of education, have been internationalising to adapt to the rapidly changing conditions of neoliberalised late-modern societies and remain competitive in highly disputed education markets. Internationality can take more or less explicit forms, and can vary in intensity in public, semi-private and private schools (Bonal, 2009; Vilalta, 2016). It usually involves, however, intensifying the presence of English and other foreign languages, institutionalizing exchange or term/year abroad programmes, and implementing international curricula such as those offered by the International Baccalaureate Organisation (IBO), which are increasingly gaining presence in schools worldwide (Resnik, 2012, 2015). This original ethnography explores the construction of the category international in two elite educational institutions from a critical sociolinguistic perspective. The focus on language(s) in processes of elitisation of education is unique, and unexplored until now in the context of Catalonia. For a period of three years I conducted ethnographic fieldwork in two schools in the Barcelona area, a ‘British international’ school and a ‘Catalan international’ school. I draw on participant observations of classes and a variety of school spaces, conversations and interviews, linguistic landscapes, and also field notes, visual data, field documents, website data and social network data, but also language-in-education policies to understand how semiotic regimes are transformed when becoming international. This happens through processes of stylisation taking place at multiple scales. My analysis shows how atmospheres, spaces, curricula and individuals are both updated and upscaled. I have explored the nuanced dynamics of distinction practices (Bourdieu, 1984) behind the internationalising processes in which schools and individuals engage; who gets to access which resources; how different participants become capitalised or decapitalised; which processes of social categorisation take place; and what consequences this has for the social and academic endeavours of students and schools. The stories of the schools and their communities reveal the frenzy for capitalisation of the (upper-)middle classes in a post-crisis Catalonia, who desire to gain access to privileged spaces or maintain their status. An international education, and a ‘very good English’ seem to be the ultimate distinctive capital. It is attractive to the traditional local clientele of these schools and increasingly to the global middle classes, who seek to compete with the best hand in neoliberalised education markets. The unique analysis of the educational strategies of the (upper-)middle classes provided in this thesis reveals the possibilities and limitations of class advancement for students with different stocks of capitals (Bourdieu, 1986). A deeper understanding of such mechanisms is crucial to understand how processes of social stratification work and emerge in the Catalan education system today