Among language users, it is a commonplace that multilingual speakers switch between languages to make themselves intelligible. Yet, sociolinguistics has had surprisingly little to say about this. This neglect traces back to early efforts to carve out a niche for the field by focusing on contexts where social rather than semantic factors like intelligibility shape multilingual practice. As fruitful as this approach has been, here I argue that it has ironically obscured much that is of social significance in multilingual practice. Focusing on prominent practices of code-mixing in Papua New Guinea, I show how their social meanings—the roles and identities they index—are tied to the way they make speech in global languages intelligible to people unfamiliar with them. In the wake of European colonialism, postcolonial nationalism, and neoliberal globalization, contexts of unevenly distributed multilingualism like this are ubiquitous. And there, intelligibility is often a prime social factor shaping multilingual practices. (Multilingualism, codeswitching, intelligibility, social meaning, global languages)*