A deductive perspective on questions and answers

Direct questions such as “Who saw Mary?” intuitively request for a certain type of answer, for instance a noun phrase “John” or a quantified noun phrase such as “A man”. Following the structured meaning approach to questions, we propose an analysis of wh-questions in typelogical grammar that incorporates the requirement for a certain type of answer into the type assigned to wh-phrases. Interestingly, the syntactic and semantic decomposition leads to a derivability pattern between instances of wh-phrases. With this pattern we can explain the difference between wh-pronouns (‘who’) and wh-determiners (‘which’), and derive whquestions that require multiple answers.