(interrogative) What amount or quantity (of something stated or implied). / (specifically, when referring to the cost of an item) What amount of money.

(interrogative) To what degree; to what extent.

(UK, slang, obsolete) you what? huh?

unspecified number / what number

Synonym of what about

how much does it cost?

Used to inquire about the weather. / (by extension, idiomatic) Indicating a change of subject to unimportant topics.

(idiomatic, informal) Why; why is it; for what reason or purpose; due to what cause?

(rhetorical question) A general statement of surprise or bemusement with regard to a particular event.; isn't that good, or unexpected, etc.

Used literally: what length. / Used literally: what duration.