句法结构是语篇结构语法化的结果。重动句来自“背景—目的”语篇结构。VP1引入背景事件 ,VP2说明语用目的 ,是小句的焦点。重动句的语用价值在于引入VP1,而不是同时引入动词V的宾语与补语。“背景—目的”关系在汉语中具有普遍性 Syntactic structure is the result of grammaticalization of discourse structure. Verb sentences come from the background-purpose discourse structure. VP1 introduce background events, VP2 pragmatic purpose, is the focus of the clause. The pragmatic value of a repetitive sentence lies in the introduction of VP1 instead of the simultaneous introduction of the verb V and the complement and complement. The “background-purpose” relationship is universal in Chinese