imperative vs grammar

imperative and grammar both are nouns.

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

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

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