This article proposes that two versions of translanguaging theory can be distinguished. These formulations do not differ in their pedagogical implications, but are framed theoretically in very different ways. Unitary translanguaging theory (UTT) endorsed by García and colleagues in numerous articles and books published since 2009 argues that the bilingual’s linguistic system is unitary and undifferentiated and that languages have no cognitive or linguistic reality. Based on this claim, UTT rejects several theoretical concepts that claim that languages do have cognitive and linguistic reality and are interconnected dynamically in our cognitive functioning. These concepts include the notions of codeswitching, plurilingualism, additive (approaches to) bilingualism, the common underlying proficiency (CUP), academic language, and the pedagogical importance of teaching for transfer across languages. Crosslinguistic translanguaging theory (CTT), by contrast, affirms the legitimacy of these theoretical concepts, and argues that bilinguals actually do speak languages, involving multiple registers and fluid boundaries. Within CTT, teaching for transfer across linguistic boundaries and bringing students’ languages into productive contact is a prime function of pedagogical translanguaging.