How to ask the obvious

English can express the basic meaning of a yes/no question in several ways, for example with or without sentential negation, and with or without subject auxiliary inversion. In this paper, we discuss how the presence of contextual clue with respect to one or the other answer to a yes/no question determines which formal variants of the question are felicitous. We then derive these syntax-pragmatics interactions from Heim’s principle of Maximize Presupposition, Stalnaker’s Bridge Principle and Grice’s Maxim of Manner, each formulated in a particular way, together with the assumption that the lexicon of English contains a silent evidential marker which exhibits familiar syntactic and semantic properties.