“…As critical as it is to accurately measure children's language environment, it is also necessary to determine if it is causally related to children's language development, either as a broad construct or as a function of specific interactions (such as adult words or adult-child conversational turns). Although there is a fairly robust literature on interventions designed to improve children's language outcomes (e.g., Cameron & Hutchison, 2009;Fricke, Bowyer-Crane, Haley, Hulme, & Snowling, 2013;Lonigan & Whitehurst, 1998), most language interventions use structured curricula, dialogic reading strategies, or milieu teaching (Walker et al, 2019). Some evidence has shown that it is possible to increase the number of adult words and conversational turns (Leung, Hernandez, & Suskind, 2019;Suskind et al, 2013); however, these studies were not designed to evaluate the causal relation between children's language environment and language development.…”