Although the importance of using students' home languages in education has been recognised for many years, home languages that are not official languages often struggle to find space in school curricula. This paper examines the ways that language-in-education policies influence the space available for non-official languages in the curriculum. It begins with a brief overview of the historical context that shapes how languages are understood in education. It then presents a critical review of some policies that allocate space to students' home language in the curriculum in order to examine certain ways that such policies both allow and constrain that space. It examines contexts that exemplify some of the key issues which students' home languages confront in educational settings, whether they are present as official languages or non-official languages, as a medium of instruction or a class subject. It then identifies some of the factors that contribute to the marginalisation of students' home languages in educational policy and practice.