What

What is a common English word that serves as an interrogative pronoun and a determiner, used to ask about identity, nature, quantity, or value? As part of the wh- word family, what introduces questions and also modifies nouns in phrases such as what time, what color, or what place.

As a direct question, what typically appears at the beginning of an inquiry: What is your name? It can also introduce indirect questions: I wonder what he wants. In relative clauses, what can function as a relative pronoun in some varieties, as in The book what I bought (more formal usage would prefer that or which). What can also occur in exclamations: What a day!

Etymology and cross-linguistic notes: What comes from Old English hwæt and is related to the Germanic wh- word set, with cognates in several languages, including Dutch wat, Icelandic hvat, and German was. These forms reflect a common Indo-European tendency to create interrogatives that inquire about identity and nature.

Usage and typology: What is a core example of a fused or separate wh- element in English, depending on construction. It influences word order in questions through subject–auxiliary inversion and appears in a range of idiomatic expressions, such as What if… or What to do next. In formal writing, what serves as a pronoun or determiner, while in some dialects it may appear in nonstandard relative clauses.