Pupils' experiences of complementary education are neglected in the research literature, yet they are highly important in terms of understanding complementary schools and their impact on pupils' educational and social identities. This article explores British-Chinese pupils' discursive constructions of the purposes and benefits of Chinese complementary schools, drawing on data from an Economic and Social Research Council (ESRC)-funded study of six Chinese schools in England, including interviews with 60 of their British-Chinese pupils. Findings demonstrate that British-Chinese pupils overwhelmingly see the purpose of these schools as perpetuating the mother tongue. They produced a variety of explanations for the benefit of this perpetuation, and we analyse how these fall under two themes: instrumental benefits, and identity. In elaborating these themes we focus particularly on the ways in which language was constructed as identity, and draw out some theoretical implications for thinking around identity and "culture". (Contains 2 tables and 10 notes.)