Effects of prior knowledge on question asking were examined. Fifth graders with little or much prior knowledge had to indicate the meaning of a set of words. Pupils could (a) not ask a question, (b) ask a global question, or (c) ask a specific question. In Study 1, prior knowledge significantly affected the number of questions asked and the pragmatic significance of the questions. In Study 2, selection was contrasted with production of questions. Pupils with little prior knowledge asked fewer specific questions and more global questions in production. The pragmatic significance of the questions was lower for all pupils in production. The pupils' questions were found wanting in information-gathering and communicative qualities. In Study 2, asking for "provisional answers" in advance of question asking strongly stimulated question asking. It presumably enhances commitment, stimulates monitoring, and alleviates social constraints in asking questions.