A discussion of classroom communication looks at the function of questions, particularly teacher-initiated pedagogical questions but also other classroom questions, either teacher- or student-initiated. Two fourth grade science lessons, conducted in Brazil by different teachers, are analyzed. Analysis focuses on the relative effects of the teachers' different styles of teaching, one textbook-centered and the other teacher-centered, on the pedagogical question, a form of interaction unique to the classroom context. Discourse examples for the analysis are given in Portuguese. The degree of teacher control over lesson content and the quality of the interactions (openness to dialogue, informative or cognitively stimulating nature, relevance, and intent to explore the student's experience) are examined. It is concluded that the more the teacher is in control, the more successfully he or she can switch from a control to a cooperative mode of interaction. While the cooperative mode is not seen as an ideal, it is considered better than the alternatives and is much more likely to emerge in the teacher-centered approach. A 14-item bibliography is included. (MSE)