Book excerpt: This book contributes to understanding research approaches for studying multilingualism in the context of contemporary superdiversity, in environments that are being dramatically transformed by transnational migration and movement of peoples. It explores language in urban contexts: the city as a site for experimentation and creativity in language practices. This involves considering theoretical frameworks in which to examine these practices, but above all, it focuses on how we do, or could do, research into these language practices and their users. What methodologies are we using to understand urban linguistic contexts? What do we want to learn? The chapters explore complex and challenging situations, capturing the evolution of new forms of language practice and changing attitudes to language in the city.