The main aim of the project is to better understand the “sentential force” of interrogative sentences, that is, the effect that the utterance of an interrogative, qua interrogative, has on the context in which it is uttered.

Stereotypically, interrogatives are considered to be devices for requesting information. In many contexts, an interrogative such as (1) is an excellent device to convey the implications in (2).

1. Is Paul an only child?

2. 1. The speaker does not know whether John is an only child.
      
   2. The speaker takes it possible/likely that the addressee knows.
      
   3. The speaker would like the addressee to see to it that the speaker knows.

At the same time, interrogative sentences can be used for many other purposes. And it is not difficult to find examples of interrogatives that lack any or all of the three implications in (2):

3. 1. Exam question:
      (In a chemistry exam)
      What is the formula for sulphuric acid?
   2. Pedagogical question:
      (Geometry teacher to student)
      Does this line bisect each of these spaces?
      
   3. Combative question:
      (Tea party representative in parliament to a Democratic colleague)
      Should taxes be raised to balance the budget?
      
   4. Discussion question
      Where shall we go for dinner?
      
   5. Discussion question
      Who had opportunity to commit the crime? (Let’s figure this out.)
      
   6. Rhetorical question (A does not stop complaining how bad the movie was.)
      B (to A): Who insisted that we go see the movie?

This sets up a theoretical puzzle. On the one hand, an utterance of an interrogative often reliable conveys the the implications in (2). On the other hand, none of them can be directly coded into the semantics of (matrix) interrogatives, seeing as we find cases of (apparently literal) uses of interrogative that lack these implications.

The main aim of the present project is to develop a theory of the sentential force of interrogatives that solves this puzzle, explaining both how interrogatives can be used for varying purposes (as in (3)), while they can, at the same time, frequently be unambiguously used to serve as requests for information.

Two subprojects are concerned with more narrowly circumscribed topics: rhetorical questions and infinitival and practical questions.