Drawing from a corpus of video-recorded classes in 6 and 7 grade groups in an Italian secondary school and in two 3 grade groups in a primary school, the article investigates one specific format used by teachers to reproach students for their untoward conduct. The analysis focuses on cases where, in contrast to other less explicit formats, teachers refer to students' ongoing behaviour as "wrong" with direct descriptions of the misconduct. Reproaches of this type employ a conditional structure in which the event and its negative consequences are described in detail. The paper argues for this specific type of reproach as displaying similarities with repair sequences in that it operates retroactively (Schegloff, 2007) to locate in prior courses of actions the source for the reproach (or the "reproachable"). Building on a detailed analysis of turn construction, word selection, and sequential deployment, the paper shows that a preference organization is in order in the accomplishment of reproaches. In comparison to prior literature on this topic, and in contrast to other documented way of treating recipients' untoward conduct as caused by their inability, the paper documents the way in which other peoples' conduct can be explicitly constructed as wrong and, as such, reproachable; thus holding the recipient as culpable for not having avoided a course of action that is not amendable. The paper argues for further research in the domain of classroom reproaches, as having implications for the understanding both of action formation mechanisms in ordinary and institutional interaction and of the different activities that contribute to the sense of formality of classroom interaction beyond instruction activities and academic talk.