本文从语用预设的角度来探讨汉语语尾助词“啊”在言谈行为中所扮演的功能。通过对高调“啊”与低调“啊”的研究发现,“啊”的功能是标志出谈话者的知识状态与现实之间的差异。并指出高调“啊”与低调“啊”相关联,它们源于同一种功能。 This article explores the function of Chinese verb auxiliary “” “ah ” in speech act from the perspective of pragmatic presupposition. Through the study of high-profile “ah” and low-key “ah”, we found that the function of “ah” is to mark the difference between the state of knowledge and the reality of the speaker. And pointed out that high-profile “ah ” and low-key “ah ” related, they come from the same function.