inappropriate vs improper

inappropriate and improper both are adjectives.

Word	Noun	Adjective	Verb	Adverb
inappropriate	No	Yes	No	No
improper	No	Yes	No	No

inappropriate (adjective)	improper (adjective)
not suitable for a particular occasion etc	not suitable or right or appropriate
not in keeping with what is correct or proper	not appropriate for a purpose or occasion
	not conforming to legality, moral law, or social convention