Based on transcripts of classroom discourse we will show how reasoning is being introduced as a teaching subject. Taking a discourse analytic approach we will focus on those discourse segments where teachers and students depart from the pattern of reasoning. We will argue that these departures are due to insufficient preparation of teachers for their role in reasoning activities. Special attention will be given to questions as a basic form of discoursive action and to how they are deployed at particular stages of discourse. It will become clear that they push the discourse on a certain direction; an observation that provides anchoring points for future studies.