Language socialization research has traditionally focused on how young children are socialized into the norms and patterns of their culture by and through language. Research in this tradition has typically conceived of the process as relatively static, bounded and relatively unidirectional. This article, based on a long-term ethnographic investigation of home language practices in Mexican-background families in the United States, confirms the theoretical and applied limitations of such a traditional approach to language acquisition. Two narratives of Mexican-background women in northern California, whose lives represent different circumstances and trajectories, show that language socialization is a dynamic and interactive process that extends throughout the lifespan as people come to participate in new communities, define and redefine themselves according to new roles, and either acquiesce in or challenge the definitions and role relationships formulated by others.