Negative polarity: A semantico-syntactic approach

Negative Polarity Items (NPIs) e.g. any, are licensed in negative sentences, questions, antecedents of conditionals, complements of adversative predicates, etc. On the other hand, Positive Polarity Items (PPIs), e.g. some, cannot appear in the scope of clausemate negation, but are licit elsewhere. I propose the following two (syntactic) principles and a (semantic) filter to account for the distribution of NPIs and PPIs: (1) NPIs are subject to Principle A of the Binding Theory. (2) PPIs are subject to Principle B of the Binding Theory. (3) UEFilter: *Polarity operator in an Upward-Entailing (UE) clause. (A potential binder for polarity items in either negation, or an empty polarity operator licensed in the Comp of non-UE clauses.) The binding principles (1) and (2) (see Progovac 1988, 1991) capture the following general facts: (4) NPIs (as anaphors) need a licenser. (5) The licenser for NPIs has to be local. (In languages with long-distance NPI licensing, such as English, NPIs raise at LF in order to be bound locally.) (6) PPIs (as pronominals) need no licenser. (7) PPIs cannot be bound by a local licenser. The role of the semantic filter (3) is to predict licensing of NPIs in exactly those environments in which they occur. An UE clause allows inferences from subsets to supersets, as in: (8) Mary ate kale. =) Mary ate a green vegetable. The switch to Upward Entailment can accommodate two problematic cases for Downward Entailment (DE) (cf. Ladusaw 1980, 1982, 1983): yes/no questions and on/y. Although neither DE nor UE, they license NPIs. While Ladusaw assumes that DE licenses NPIs directly, it is claimed here that a polarity operator is licensed in the Comp of a non-UE clause, and that the operator in turn licenses NPIs. This assumption can account naturally for a set of otherwise puzzling facts: (i) that non-negative