Research has established that classroom verbal interaction typically involves turn taking cycles described as "teacher solicits,""pupil responds," and "teacher reacts." A study examined the question/answer cycles occurring within 36 videotaped language arts lessons conducted by six elementary school teachers and made inferences regarding what students must know about repeated cycles of turn-taking during classroom discourse in order to comprehend discussion. The study was confined to three main sequences: (1) the topical or independent relationship, in which two adjacent question cycles are structurally separate, but frequently related by topic; (2) the conjunctive relationship, in which two or more question cycles are tied together because the same question is asked of more than one pupil; and (3) the embedded relationship, in which one question cycle is contained within another because the teacher reaction involves a new solicitation. Graphic displays of the taped lessons suggested that the structural sequencing of question cycles varied a great deal from lesson to lesson, and that much of this variation was derived from the instructional strategy or teaching procedure being used. Comprehension of a conjunctive cycle appeared to depend on a pupil not only realizing that the same question was being asked more than once, but also understanding why the question was being repeated. Comprehension in an embedded cycle appeared to depend on the pupil recognizing that the teacher's reaction did not close out the matter at hand, but that the topic was being pursued further. (HOD)