NPI Licensing in Temporal Clauses

This paper offers a systematic approach to NPI licensing in temporal clauses based on a uniform analysis of temporal connectives as relations between times and relying on appropriate type shifting for compositional buildup. The quantificational force commonly associated with temporal connectives is attributed to the operators earliest and max operating on the temporal clause and effecting the necessary type-lowering for a connective to compose with a clause. An implication about the truth of a temporal clause with any kind of temporal connective is a semantic presupposition due to a definedness condition associated with earliest and max. Based on Beaver & Condoravdi (2003, in progress), I show that veridical and non-veridical before induces a reversal in specificity ordering when combined with a temporal clause, and so does after when construed with max. I then show that the exceptional NPI licensing in until and since clauses is due to a reversal in specificity ordering induced after the composition of these clauses with main clauses of a particular kind. Crucial throughout is the more restricted, presupposition-dependent notion of entailment, Strawson-entailment, proposed by von Fintel (1999).