* Pronoun: It can act as a pronoun when it stands in for a noun or noun phrase.
* Example: "What did you say?" (Here, "what" refers to something that was said.)
* Interrogative Adjective: It can be an interrogative adjective when it modifies a noun.
* Example: "What time is it?" (Here, "what" modifies the noun "time")
* Interrogative Adverb: It can be an interrogative adverb when it modifies a verb, adjective, or other adverb.
* Example: "What happened?" (Here, "what" modifies the verb "happened")
It is not a verb. Verbs express actions or states of being. "What" doesn't do that.