In an address delivered the Annual Convention of the Teachers of English to Speakers of Other Languages (TESOL) in March of 1974, Wallace E. Lambert introduced the notion that bilingualism might be either additive or subtractive (Lambert 1973). Over the years, these terms have been misconstrued to simply refer to the cumulative effect on the first language (L1) of learning a second language (L2). When the second language adds resources or skills to the inventory that are already active within a student’s first language, the L2’s effect can be characterised as additive bilingualism. Conversely, when the second language inhibits (or prohibits) the development of skills in the student first language, the L2s effect is characterised as subtractive bilingualism. However, Lambert does not suggest that the different outcomes in bilingual contexts — namely, additive or subtractive bilingualism — are socially-neutral effects; instead, he argues for the sociolinguistic nature of these two types of bilingualism. Lambert (1973) explains that additive bilingualism occurs in contexts characterised by ‘bilinguals using two languages both of which have social value and respect’ (pg. 26). Subtractive bilingualism, on the other hand, is characteristic of contexts where ‘ethnic minority groups who because of national educational policies and social pressures of various sorts are forced to put aside their ethnic language for a national language’ (pg. 26). While much of Lambert’s research was focused on factors related to the development of bilingualism in French and English in Canada, the influence of social factors and their relationship to the development of additive or subtractive bilingualism can be measured in a number of other linguistic contexts.