“…However, type and tokens are not the only relevant factors in the input. The quantity of other aspects of children's language learning environments also matters, including frequency of specific syntactic frames (Cameron-Faulkner, Lieven, & Tomasello, 2003;Huttenlocher et al, 2002;Huang, Leech, & Rowe, 2017;Naigles & Hoff-Ginsberg, 1998;Rowe, Leech, & Cabrera, 2017) as well social behavioral factors including turn-taking, coordinated attention to the topic of speech, and parental responsivity (Bakeman & Adamson, 1984;Hirsh-Pasek et al, 2015;Hoff, 2006;Landry, Smith, Swank, Assel, & Vellet, 2001;Ninio & Bruner, 1978;Suanda, Smith, & Yu, 2016;Tamis-LeMonda, Bornstein, & Baumwell, 2001;Tamis-LeMonda, Kuchirko, & Song, 2014;Tomasello, 1988). Caregiver child joint attention and the timing of the naming event with respect to the child's focus of attention on the labeled referent are all relevant to real-time learning (Cartmill et al, 2013;Dunham, Dunham, & Curwin, 1993;Yu & Smith, 2012).…”