Research findings: Language development subcontexts within 20 Head Start classrooms were studied by observing teachers' child-directed talk during free play, mealtime, and book reading. In each context, observers coded all child-directed statements, directives, and questions, noted instances of pretend talk and decontextualized talk, and rated the richness and sensitivity-responsiveness of teachers' talk. Rates of child-directed talk were similar across contexts, but the challenging features of teachers' talk varied substantially across contexts: pretend talk occurred almost exclusively during free play, decontextualized talk was most common during mealtime, and ratings of richness were greatest during book reading. Higher rates of pretend talk and decontextualized talk and higher ratings of richness were associated with higher ratings of sensitivity-responsiveness. Rates of child-directed talk did not differ reliably for Lead Teachers and Assistant Teachers. Implications for practice: Professional development efforts may focus productively on helping Head Start teachers to recognize natural opportunities for different types of challenging talk in different classroom contexts. In the majority of classrooms, encouraging teachers to engage in more child-directed talk carries little risk of reducing the quality of sensitive-responsive caregiving. Assistant Teachers play a major role in Head Start classroom language environments and should be included in professional development activities focused on children's language skills.