This study examined the quality of preschool teachers' interactive conversations with three- and four-year-olds in two Head Start classrooms serving children from low-income families in the United States. Over a period of 20 weeks, 10 bi-weekly observations of conversations (totaling 15 h per classroom) were conducted in one small-group (Play Time) and two large-group (Breakfast Time and Circle Time) contexts. The teacher-child verbal interactions were transcribed and coded using the Teacher Interaction and Language Rating Scale (TILRS) to determine the frequency of responsive language strategies employed by the teachers across the three contexts. The two teachers applied Child-Centered Strategies and Interaction-Promoting Strategies the most during Circle Time, followed by Play Time, and the least during Breakfast Time. While it was observed that both teachers did talk to the children face to face frequently across contexts, they rarely used Language Modeling Strategies to engage them in cognitively challenging conversations. Implications for professional development are discussed. (author abstract)