Due to the heterogeneous onglll of university students and the diverse language use guidelines in their departments, as welI as the peculiar language contact that takes place in the territory of Catalonia, the University of Barcelona is one of the most linguisticalIy complex universities of the occidental world. Catalan, Spanish and English are seen as enriching elements although dissenting voices do arise concerning the use of each of these languages. For this reason, we carried out a qualitative study, asking thirty-two students of the University of Barcelona (UB), the firsr Caralan University, how they perceive and face the chalIenges of their sociolinguistic environment. Briefly, in this article we study-in the first place-how students view the fact that English is becoming a language of insrruction; and secondly, we analyse the main arguments that local students use to justify their linguistic ideology regarding Erasmus students.