grammar vs imperative

grammar and imperative both are nouns.

Word	Noun	Adjective	Verb	Adverb
grammar	Yes	No	No	No
imperative	Yes	Yes	No	No

grammar (noun)	imperative (noun)
the branch of linguistics that deals with syntax and morphology (and sometimes also deals with semantics)	some duty that is essential and urgent
	a verb in the imperative mood.
	a mood that expresses an intention to influence the listener's behavior

grammar (adjective)	imperative (adjective)
	requiring attention or action
	relating to verbs in the imperative mood