Asking questions is one of the most common activities of mathematics teachers at various levels of education. Moreover, the way the teachers formulate questions has profound impact on the results of teaching, especially on their pupils' reasoning process. Erotetic logic is frequently presented in a very formal manner. In this paper, we restrict our attention to these aspects of erotetic logic that can turn it into a useful framework to describe various didactic situations. In particular, the paper contains remarks on question structure, its didactic function, certain criteria of correctness of questions, and various classifications of questions that can be useful for teaching. Finally, we discuss some strategies and techniques of asking questions and encouraging pupils to pose questions.