Question
A question is an utterance which serves as a request for information. Questions are sometimes distinguished from interrogatives, which are the grammatical forms typically used to express them. Rhetorical questions, for instance, are interrogative in form but may not be considered bona fide questions, as they are not expected to be answered. Questions come in a number of varieties. Polar questions are those such as the English example "Is this a polar question?", which can be answered with "yes" or "no". Alternative questions such as "Is this a polar question, or an alternative question?" present a list of possibilities to choose from. Open questions such as "What kind of question is this?" allow many possible resolutions. Questions are widely studied in linguistics and philosophy of language. In the subfield of pragmatics, questions are regarded as illocutionary acts which raise an issue to be resolved in discourse. In approaches to formal semantics such as alternative semantics or inquisitive semantics, questions are regarded as the denotations of interrogatives, and are typically identified as sets of the propositions which answer them. Definitions Linguistically, a question may be defined on three levels. At the level of semantics, a question is defined by its ability to establish a set of logically possible answers. At the level of pragmatics, a question is an illocutionary category of speech act which seeks to obtain information from the addressee. At the level of syntax, the interrogative is a type of clause which is characteristically associated with questions, and defined by certain grammatical rules (such as subject–auxiliary inversion in English) which vary by language. Some authors conflate these definitions. While prototypical questions (such as "What is your name?") will satisfy all three definitions, their overlap is not complete. For example "I would like to know your name." satisfies the pragmatic definition, but not the semantic or syntactic ones. Such mismatches of form and function are called indirect speech acts. Uses The principal use of questions is to elicit information from the person being addressed by indicating the information which the speaker (or writer) desires. A slight variant is the display question, where the addressee is asked to produce information which is already known to the speaker. For example, a teacher or game show host might ask "What is the capital of Australia?" to test the knowledge of a student or contestant. A direction question is one that seeks an instruction rather than factual information. It differs from a typical ("information") question in that the characteristic response is a directive rather than a declarative statement. For example: A: When should I open your gift? B: Open it now. Questions may also be used as the basis for a number of indirect speech acts. For example, the imperative sentence "Pass the salt." can be reformulated (somewhat more politely) as: Would you pass the salt? Which has the form of an interrogative, but the illocutionary force of a directive. The term rhetorical question may be colloquially applied to a number of uses of