This chapter is framed by the three questions related to learning in Practice Theory posed by Johannes Wagner (2008): (1) What is learned?; (2) Who is learning?; and (3) Who is participating in the learning? These questions are addressed in two learning theories: Language Socialization and Situated Learning theory. In Language Socialization, the answer to the question of what is learned includes not only language but also ways of acting, ways of feeling, and beliefs. When these are acknowledged as what is learned, the challenges for second language (L2) learners are seen in a new light because using an L2 involves a battle for subjectivity in a new community. Learning a new language involves becoming part of a new community, either a classroom community or a community outside the classroom. The concept of community of practice is introduced in this chapter to show how what is shared in communities is not only a language but a repertoire of styles of communicating. How newcomers approach participation in a community is aptly described in the studies of Situated Learning or legitimate peripheral participation that are reviewed in this chapter. The chapter concludes with analyses of two examples of situated learning. (Contains 1 figure, 1 table and 11 notes.)