This chapter reviews recent studies of cognitive and linguistic correlates of exposure to two languages in infancy and early childhood. Most of the studies reviewed directly compare monolingual children to those who are exposed to two languages. The cognitive correlates include enhanced executive functioning (especially inhibitory control), and Theory of Mind. The linguistic correlates include smaller vocabularies in each language, different word-learning strategies, slower lexical access, and enhanced pragmatic and metalinguistic skills. Issues in interpreting group differences, in particular, whether such differences should be interpreted as deficits, are discussed.