Local and Global Implicatures in Wh-Question Disjunctions

It has been observed that wh-questions cannot be joined disjunctively, the suggested reasons being semantic or pragmatic deviance. We argue that wh-question disjunctions are semantically well-formed but are pragmatically deviant outside contexts that license polarity-sensitive (PS) items. In these contexts the pragmatic inadequacy disappears due to a pragmatically induced recalibration of the implicature triggered by or (as argued in [1]). We propose that the alternative-inducing property of or has as its syntactic correlate the feature [+σ] (cf. [2]), thus forcing the insertion of the operator O\(_{\mbox{\scriptsize{\sc alt}}}\), which is responsible for the computation of implicatures at different scope sites. Importantly, the licensing of the PS property of wh-question disjunctions cannot be reduced to the licensing of a lexical property of or but also depends on the semantics of the disjoined questions.