improper vs inappropriate

improper and inappropriate both are adjectives.

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

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