Both questions as abstract objects and the speech acts, here called requests, by which we ask them play an enormous role in all argumentative practices. Nonetheless, there is hardly a proper systematic treatment of questions and requests in current argumentation theories. This paper is a first attempt at providing such a systematic treatment. This is achieved by following the ideal model of a critical discussion as elaborated over the years by the Amsterdam school of pragma-dialectics. After introducing the distinction between questions and requests, the paper sets forth and illustrates the norms of questioning which implicitly underlie the four stages of a critical discussion in the standard order: confrontation, opening, argumentation, and conclusion. Among other things, it is shown that crucial insights of pragma-dialectics are illuminated by the questioning perspective, in particular the distinction between single and multiple differences of opinion, the duties of the antagonist and protagonist roles, the precise character of the argumentation stage, and the different ways in which a disagreement can be resolved.