Global mobility has dramatically changed the demographic profile of universities in predominantly English-speaking countries. Many international students choose study abroad opportunities in countries such as Australia where there are also many local students with diverse linguistic backgrounds. However, the plurality of languages, cultures and knowledge systems are largely rendered invisible in higher education contexts where English dominates. This paper reports on the first of two cases studies in a project which explored how undergraduate students experience a translanguaging approach (García & Wei, 2014) to develop their English language capability in order to study through English. This was part of an action-based research intervention which sought to develop academic proficiency in both English and the primary language/s of students, and their intercultural capabilities, simultaneously, through explicit encouragement of students’ use of their linguistic, cultural and knowledge repertoires, and their reflective engagement with the process. This report outlines data and findings from student participation in three English as additional language courses during 2014 and 2015. Data include ethnographic observation of student engagement in classes, student interviews and diagnostic analysis of student writing. Drawing on multilingual teaching and learning pedagogies (Heugh, Li & Song, ftc.), including translanguaging, students’ were encouraged to build on their linguistic, cultural and epistemological resources to expand their academic language repertoires. The findings highlight how students do this while developing their metacognitive awareness of linguistic and cultural diversity and their multilingual repertoires. It draws attention to the pedagogical value of students’ academic proficiency in both primary language and English and this has implications for developing a more robust pedagogy and theory of translanguaging and intercultural communication. This is significant in the context of 21st century human mobility when we consider that many of these students will be required to communicate in their social and professional lives across multiple languages and cultures.