interrogatory vs interrogative

interrogatory and interrogative both are nouns.

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

As adjectives, interrogatory and interrogative are synonyms defined as:

interrogatory and interrogative: relating to the use of or having the nature of an interrogation

interrogatory (noun)	interrogative (noun)
formal systematic questioning	a sentence of inquiry that asks for a reply
	some linguists consider interrogative sentences to constitute a mood

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