If there are few student questions, it may be that students are not paying attention closely enough or not thinking about the topic at hand. Sometimes this is an indication that you need to work on developing a more engaging or varied approach to your class. However, often students do not ask questions because they fear their questions will be dismissed, ignored or brushed aside. It is possible that they feel the instructor does not want students to ask questions. If a student feels that his or her questions were unwelcome, that student may never ask another question during the entire semester.
Teachers discourage questions for a number of reasons.
Sometimes they are insecure and do not want to lose control by opening the classroom to questions that they may not be able to readily answer. The potential for loss of control and loss of face is real. However, it is also true that the fear of this happening is often exaggerated. The teacher must weigh the advantages gained by permitting and encouraging questions against the need to maintain tight control. Students need time to think about the question and prepare their responses.