This study approaches teacher learning from a dialogical viewpoint where lecturers' voices used in a training course context reflect how lecturers generated new professional discourse. The design of the training course considered the analysis of several critical incidents (CIs) in online teaching. An analytical framework based on lecturers' discourse and ways of thinking about teaching was used to identify types of renaming teaching practice. The empirical element of the study analysed the written utterances about teaching provided by 12 online instructors in order to determine what kinds of new discourse emerged during the analysis of 15 CIs in online teaching. Results showed that local discourse is the lecturers' most commonly used discourse, prototypical incidents generated more professional discourse than personal and real CIs, and professional discourse can be created by means of at least nine different ways of articulating discourse. On the basis of these results, some pedagogical implications for lecturer learning are discussed.