The internationalisation of higher education has increased the visibility of linguistic diversity in universities worldwide. However, classroom practices do not necessarily reflect this diversity. This study explores how teachers and students manage plurilingual resources while learning Catalan during study abroad. The analysis applies [Moore, E., Nussbaum, L., & Borràs, E. (2013). Plurilingual teaching and learning practices in 'internationalised' university lectures. "International Journal of Bilingual Education and Bilingualism," 16(4), 471-493] categorisation of plurilingual practices to construct subject content knowledge in two international universities in Catalonia. The results show how teachers accept the students use of other languages in class, even though they do avoid employing it themselves. Using Spanish allows the students to reach a greater level of complexity and challenge the teacher's position in class as perhaps less of a plurilingual speaker than the students. We suggest that a Catalan language course which incorporates Spanish in its teaching methodology in a planned and organised way would be doubly beneficial, because it would speed up the acquisition of Catalan and stimulate the social practice of multilingualism as the students would learn how to move between Catalan and Spanish in Catalonia and understand the discourses they will encounter during their stay.