本文从形式语义学的角度研究汉语性质形容词作谓语的不完句效应。在对性质形容词作谓语能够完句的各种句法结构进行分析的基础上,本文指出相关结构都属于焦点位置,性质形容词作谓语能否完句与这些焦点位置直接相关。基于这一概括,本文进一步对这一关联进行了理论分析,提出性质形容词谓语句是类指句。文章认为,焦点能够提供变量,从而将性质形容词作谓语要求出现在焦点环境归因于Kratzer(1995)提出的“禁止空量化”原则。 This article studies the imperfect sentence effect of Chinese adjectives as predicate from the perspective of formal semantics. Based on the analysis of various syntactic structures of adjectives which can finish sentences, this paper points out that the related structures all belong to the focal position, and whether the adjectives are the predicates can be directly related to these focal positions. Based on this generalization, this article makes a further theoretical analysis of this connection, and proposes that the adjective predicate of the nature is a classifier. In the opinion of the article, the focus can provide variables, and appearing the adjectives of nature as the predicate requirements in the focus environment is attributed to the principle of “prohibiting empty quantification” proposed by Kratzer (1995).