Abstract
This paper aims to explore the semantic change of the Chinese modal ‘GAI’ in light of “Frame semantics” (Fillmore1982) and “Grammaticalization” (Hopper & Traugott 2003[1993]). First, it is observed that ‘GAI’ in modern Chinese has three types of construction: NP+GAI+VP, NP1+GAI+NP2+VP and GAI+you duo me+NP/AP. Second, the core meaning of modal ‘GAI’ is “to perform some action due to some force”, which can be divided into deontic and epistemic in regards to different presuppositions and profiles. Finally, the grammaticalization of ‘GAI’ is explored based on diachronic data.