The Heritage Language Variation and Change Project (HLVC) examines usage and change in a range of non-official languages spoken in Toronto, a city where more than 2 million residents’ home language is not one of Canada’s official languages. This multilingual and multi-level project pushes variationist research beyonds its monolingually-oriented core by synthesizing methods for examining both intra- and interlanguage choices made by multilingual speakers, a group that comprises well over half the world’s population.