This article reviews a range of ways in which issues of national identity have been shown to be linked with the topic of language. We suggest that there is scope for development both of the theoretical underpinning to claims made about the nature of these links, and also, in consequence, to the methodological approaches appropriate to empirical investigations of them. Here, we explore the ways in which aspects of the social world such as those summarised above are understood theoretically. The first part of the paper argues that debates about the relationship of languages to forms of social identity, particularly those associated with nationalisms, often make a number of assumptions - about languages, about collectivities and about social agency. The second part
interrogates these assumptions and proposes the utility of realist theory in evaluating claims in this area. In the final part of the paper, we outline the methodological implications of our argument.