极项理论中衍推关系的评估层面

Entailment evaluation in the theory of polarity sensitivity

否定极项能够出现在only句、“只”字句以及其他一些语言中排他焦点句的非焦点位置,而这些位置表面看来并不具有向下衍推(DE)的性质,这给经典的衍推极项理论带来很大挑战。文章分析排他焦点句的量化结构,将其非焦点部分投射到全称量化三分结构的限定域部分,并论证全称量化限定域的向下衍推性,从而化解了其对衍推极项理论形成的威胁。本文认为极项理论中的衍推关系,需要在逻辑量化层面而非句子表面进行评估,逻辑层面的向下衍推语境才是允准否定极项的必要条件,抽象为LF-DE条件,LF-DE对各种极性现象具有普遍的解释力。

The downward entailing(DE)hypothesis of negative polarity licensing argues that negative polarity items(NPIs)can only be licensed in the scope of DE operators.However,this hypothesis cannot explain why NPIs can also be licensed by the non-DE only-sentences.This study maintains the basic assumption of the DE hypothesis and resolves its problem by relocating the entailment evaluation from surface structure(SF)to the logical form(LF).Under the new LF-DE hypothesis,the connection between every and only is found by analyzing them via the tripartite structure introduced by the operator of universal quantification.It is also proved on logical and semantic levels that the restrictor introduced by only is downward entailing.Besides,the non-focal part of only-sentences in which NPIs appear is downward entailing at LF as well.Based on the above,it is shown that the new LF-DE hypothesis proposed by this paper is more applicable and can explain all polarity-sensitive cases.