Or what?

This paper develops an argument that discourse considerations are crucial in the semantics of questions by looking at the case of English or what questions. We argue that what in these questions is a discourse pronoun anaphoric with the 'Question Under Discussion', and show that this account explains the range of variation in how or what questions are interpreted in context, compared to other question types. This accounts for the fact that OWQs can be used as plain information seeking questions, as rhetorical questions, and also as questions that express insistence about receiving an immediate answer. Along the way we present empirical arguments that or what questions do not involve sluicing, though they can best be compared to the phenomenon of antecedent-less 'pseudo-sluicing'.