Classrooms are dynamic spaces of teaching and learning, where language and culture are intertwined in remarkable ways. The theory of language socialization explores how sociocultural practices in classrooms help to shape language learning and development. This collection is the first of its kind to bring together research on this fascinating concept. It presents 10 case studies, based on linguistic and ethnographic research conducted in classrooms located within communities in North America, Europe and India, spanning learners from preschool, to primary and secondary school, to university. Following an introduction that discusses the theory and core concepts of language socialization, the volume is divided into three central themes: socializing values, dispositions, and stances; socializing identities; and language socialization and ideology. Both new and more experienced researchers will appreciate its new insights into how language socialization is carried out across the globe.