Abstract: | The article explores the perplexing outcomes of comparative research projects in London and Paris on language change in multilingual areas of the cities populated by large numbers of recent immigrants with very diverse language backgrounds. In London, as in many other northern European cities, language contact on such a large scale has resulted in the emergence of a “multiethnolect”: a repertoire of innovative linguistic forms used by young people of all ethnicities, including monolingual non‐immigrant speakers. In Paris, however, there was no such repertoire. I propose four factors that are necessary for a multiethnolect to emerge and that explain why similar processes of population movement, immigration, and globalization have produced such different linguistic outcomes in London and Paris. These factors remind us that language evolution, like language use, is constrained not only by the social characteristics of individuals but also by the socio‐cultural historical contexts in which individuals live. |