Back-and-forth conversations with adults are critical for developing children's language, and, therefore, an important part of the early childhood classroom learning environment; however, the specific nature of teacher feedback, one component of teacher-child conversations, on child language has not been widely studied. This article examined preschool teacher-child conversations during interactive book reading. We coded and analyzed the frequency and content of teacher talk, including feedback, among 20 teachers (11 who participated in a language and literacy intervention; 9 in business-as-usual instruction). Findings revealed that, particularly when teachers were guided on how to initiate and sustain intentional conversations, more conversations took place and were associated with higher overall classroom quality on a commonly used global assessment (the Classroom Assessment Scoring System); likewise, more teacher feedback occurred in intervention classrooms. The frequency of teacher feedback was uniquely linked to children's vocabulary learning on standardized measures beyond the effects of global classroom quality. Findings support the importance of understanding and supporting teacher feedback as an essential part of classroom conversations. [This paper was published in "Topics in Language Disorders" v42 n4 p336-359 2022.]