In traditional classroom discourse, the teacher controls the discussion, asking most of the questions and calling on students to respond. This model does not work well for the inquiry-based classroom, which depends on engagement, peer interaction, and student ownership of learning. In this article, the authors present an alternative framework for classroom discourse--the tetrahedron, which consists of four equilateral triangles. This framework suggests that the teacher and students are working together for a common purpose of shared learning. Practical suggestions for putting the tetrahedron model into practice in your classroom are included. (Contains 2 figures.)