This chapter investigates the role of social interaction in the development of formulaic competence in L2 German during study abroad (SA), focusing on SA as a multilingual environment. It presents longitudinal case studies of four language students: two were spending a semester abroad in the target language (TL) country (Germany), two in a non-TL country (Spain and Russia). Formulaic development was measured pre- and post-SA, and students’ social interaction patterns were explored using a questionnaire plus interviews. Results suggest that the destination country does not influence students’ formulaic language development per se, and that language learners who engage in meaningful L2 social interaction with members of the L2 community, including in a non-TL country, can make progress in L2 formulaic language when abroad.