“…Previous work demonstrated that word frequency, grammatical complexity, and gender differences in language input influence early vocabulary size and growth (Huttenlocher, Haight, Bryk, Seltzer, & Lyons, 1991;Snow, 1972). In a similar way, several dimensions of maternal responsiveness predict children's acquisition of language milestones as early as 9 months of age (Tamis-LeMonda, Bornstein, & Baumwell, 2001) and even into the fourth year of life (Hudson, Levickis, Down, Nicholls, & Wake, 2015). Qualitative aspects of language exposure have been much less studied in the bilingual literature.…”