As a result of growing globalization, the learning experience of second/foreign (L2/FL) language learners has been inextricably linked to complex social structures and networks. Through a sociolinguistic lens, this paper provides a critical review of L2/FL learning, identity negotiation, and community of practice in the face of incremental changes in linguistic systems and norms concomitant with gradual transformations in politics, society, and economics. In different social structures, identity emerges and is formed in complex social, cultural, and interactional phenomena. Due to the complicity of identity work, methods employed in identity and language learning entail both qualitative and quantitative approaches, including micro and macro analysis of language use, and ethnographic study on social and cultural practices. It is examined in this paper how identity has been conceptualized in sociocultural theories of language learning. Moreover, I probe into the context in which language learning takes place and discuss to what extent L2 and FL communities overlap and exchange. I argue for a perspective on the "circumstantiality" of language learning and communities of practice. At the end of this paper, reflections on identity work are offered and implications for language learning are discussed in the hope of relevant issues to be further explored.