In this study, we investigated how questions influence problem (re)framing and idea shaping in design discourse. We analysed the question-asking behaviour of a multidisciplinary group of students who were tasked with designing new birthday celebration concepts. We focused on the sessions that took place during the idea generation phase of the project. Our analysis showed that high-level questions facilitated the emergence of inflection moments during idea generation. It also illustrated that, prior to the inflection moments, reflection built the basis on which high-level questions were formulated. We interpreted that type of reflection as resistance to design fixation. Based on our findings, we proposed a model of how design inquiry facilitates inflection moments during idea generation and counteracts design fixation.