按论元指派的原则，本文论证汉语客事宾语在句法结构上必须是谓语动词的补足 语。如果客事宾语出现在不同的句法位置，它是从动词的补足语位衍生而来的，原 因是客事宾语要作焦点。这跟呼应语言（如英语）中的客事宾语为了呼应而移位类 似。不同的是，焦点不完全是强制性的，而呼应则是普遍性的。本文分析的优点是，不论客事宾语出现在何种句型，其语义和句法结构位置是统一的。 According to the principle of argument assignment, this paper argues that the Chinese guest object must be a complement of the predicate verb in syntactic structure. If the client object occurs in a different syntactical position, it is derived from the complements of the verb because of the client object. This is similar to echoing the client object in the language (eg, English) to echo. The difference is that the focus is not entirely mandatory, and echo is universal. The advantage of the analysis in this paper is that the semantic and syntactic structures are uniform regardless of the type of client object.