Abstract: This paper first characterizes ‘hái bù VP’ as an idiomatic construction, examining its polymorphic usage to explore connections between interrogative, rhetorical, exclamatory, and declarative moods. Subsequently, based on the universal sociopsychology of negativity bias in language use, it investigates the motivators behind the redundant ‘hái bù VP’ structure, demonstrating that the negative particle ‘bù’ expresses the speaker’s sense of surprise. Furthermore, from the perspective of interactional pragmatic effect, the redundant ‘hái bù VP’ structure can be regarded as a form of implicit polyphony, exhibiting distinct characteristics of communicative interactivity. The object VP associated with the negation particle ‘bù’ reflects the speaker’s viewpoint, while simultaneously serving an intervening function by introducing the listener’s voice.