whphrase

A whphrase is a linguistic unit consisting of a wh-word plus its complements, forming a phrase used to ask questions or to introduce relative clauses. Wh-words include what, which, who, whom, whose, where, when, why, and how, as well as multiword forms such as how many, how much, and how long. The whphrase is the central element whose value is sought or referenced in the clause.

In English and many related languages, wh-phrases commonly move to the front of the clause in interrogative and some relative constructions, creating a wh-question or a wh-relative clause. For example, in What did you eat? the wh-phrase what appears at the left edge, while in The book that you read uses a relative form with a different syntactic position for the embedded wh-phrase. Wh-phrases can function as subjects, objects, or complements, depending on the verb and clause structure.

Across languages there is variation in how wh-phrases are realized. Some languages use overt movement to a front position, others employ wh-in-situ, where the wh-phrase remains in place and the question is indicated by intonation or context. Certain languages require explicit markers for wh-phrases or differences in case marking, while others allow free relatives built around wh-phrases.

Wh-phrases are central to theories of question formation, extraction, and scope. They interact with island constraints, binding, and operator movement, and they contrast with non-wh-question forms and with non-wh relatives in syntactic analyses.