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. For instance; 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.