Rhetorical questions are traditionally considered a pragmatic and semantic issue. In this paper, I discuss the rhetorical expression gwai in Cantonese. By arguing that gwai, though base generated as a postverbal suffix, Agrees with the Speaker Phrase, Addressee Phrase, and Commitment Phrase located at the expressive component above CP, I suggest rhetorical questions may be analysed syntactically. The proposal may even be extended to other rhetorical expressions in Chinese. This study provides a new perspective not only to rhetorical questions and expressive components in the minimalist framework, but also to the study of SFPs and intonation in Cantonese.