interrogate vs interrogative

interrogate is not a noun while interrogative is a noun.

Word	Noun	Adjective	Verb	Adverb
interrogate	No	No	Yes	No
interrogative	Yes	Yes	No	No

interrogate (noun)	interrogative (noun)
	a sentence of inquiry that asks for a reply
	some linguists consider interrogative sentences to constitute a mood

interrogate (adjective)	interrogative (adjective)
	relating to the use of or having the nature of an interrogation
	relating to verbs in the so-called interrogative mood

interrogate (verb)	interrogative (verb)
pose a series of questions to
transmit (a signal) for setting off an appropriate response, as in telecommunication