| There is a peculiar linguistic phenomenon of interchangeable subjects and objects in Chinese while word order is the most important grammatical means of Chinese. This dissertation systematically presents the opinion that there is common mechanism among different types of sentences with interchangeable subjects and objects which contain different structures and functions. The common mechanism is that weakened action of predicate is vital for sentences with interchangeable subjects and objects. Meanwhile, Interchangeability is based on appropriateness for language being social. In the dissertation, it's proved from the standpoint of pragmatics and speech act theory that the change of subjects and objects corresponds to various social needs, which entails the foundation in the world outside languages. It's also pointed out word order is flexible while the components of sentence is fixed and sentences with interchangeable subjects and objects can't invalidate the role of word order in Chinese. |