Almost all low- and middle-income postcolonial countries now use English or another dominant language as the medium of instruction for some, if not all, of the basic education cycle. Much of the literature about language-in-education in such countries has focused on the instrumentalist value of English, on one side, and the rights of learners to high quality mother tongue-based education, on the other. The polarised nature of the debate has tended to leave issues related to the processes of learning in English as a Medium Instruction (EMI) classrooms under-researched. This book aims to provide a greater understanding of the existing challenges for learners and educators and potential strategies that can support more effective teaching and learning in EMI classrooms. Contributions illustrate the impact that learning in English has on learners in a range of regional, national and local contexts and put forward theoretical and empirical analyses to support more relevant and inclusive educational policies. This volume was originally published as a special issue of Comparative Education.