Classroom talk patterns are notoriously resistant to change. This article examines changes in one fifth-grade teacher's discourse practices and beliefs as she and the author engaged in inquiry-driven professional development. Discourse analysis of class discussions and qualitative analysis of transcripts of professional development sessions indicated that the teacher made three important shifts: opening the floor for student talk; offering responses that were more contingent on student contributions; and moving toward yielding interpretive authority over discussions. Supported, teacher-driven inquiry combined with introduction of semi-scripted sentence stems selected to address a teacher-identified concern helped the teacher move toward more fluid, unscripted, effective discussions.