Medium of instruction and multilingual contexts: unravelling the questions and unpacking the challenges

In times and contexts where multilingual classrooms and educational settings are the norm, attention tomedium of instruction (MOI), and to practices around language use in teaching and learning, is unavoidable. Prioritising one language as the MOI over others arguably has a profound impact on all languages and their various stakeholders in multilingual contexts. MOI policy decisions, their enactments, and how these realise broader geopolitical and socio-political agendas in multilingual contexts present another layer of complexity in questions regarding MOI in multilingual education. MOI is deployed as policy and promoted as practice to pursue diverse objectives, but enactment in classrooms often provokes unexpected outcomes and multilingual practices that illustrate the creativity and resourcefulness of language users. As language users—teaching practitioners and their students—respond to fluidity and complexity in language ecologies of the current multilingualism (Aronin in Learning and using multiple languages: current findings from research on multilingualism. Cambridge Scholars Publishing, Newcastle upon Tyne, UK, pp 1–28, 2015), researchers are in turn responding to investigate and analyse rich sources of data that can reveal the realities of moment-to-moment practices and that can offer new or alternative approaches and responses to the needs of diverse stakeholders. This chapter foregrounds how these challenges and complexities interact in relation to choices, implementations, and enactments ofMOI in multilingual settings. It also explores how they impact on educational processes, developments and outcomes, as well as broader social and (geo)political agendas, and contributions researchers make to understand these.