Background: In linguistically diverse contexts, language learning and the building of quality relationships are key -- and intertwined -- educational goals. These aspects are particularly important in learning communities where the language of instruction may represent an additional language for most students. It is, therefore, essential to identify activities that promote quality interactions in the language to be learnt. Interactive Groups (IGs) is an educational action that aims to create conditions conducive to promoting relationships of solidarity, collaborative interaction, and effective participation for all learners. There is a need to investigate how IGs may be most beneficially used with languages of instruction that represent minority languages within the given sociolinguistic context and are a second language for most students, as is the case with the Basque language in the Basque Country. Purpose: This exploratory case study sought: (1) to explore the influence of IGs on the learning of Basque (a minority language and the language of instruction at school) as a second language for most students; and (2) to investigate the IGs in relation to students' collegial relationships. Methods: Data were collected via a total of 14 interviews with students, teachers, school staff and volunteers, along with the consideration of material from 28 IGs. In-depth qualitative analyses were conducted. Findings: Analysis suggested that the increased opportunities to communicate in the classroom during IGs bolstered the levels of collaborative language learning interactions. In addition, the scaffolding and supportive exchanges between students contributed to the development of collegial friendships. Conclusion: In our small-scale study, interaction in Basque and friendly collaboration between students developed and was enabled within the IGs. This highlights the potential of IGs to foster the learning of additional and minority languages, as well as to promote the growth and flourishing of positive relationships between students involved in the activities.