inability vs ability

inability and ability both are nouns.

Word	Noun	Adjective	Verb	Adverb
inability	Yes	No	No	No
ability	Yes	No	No	No

inability (noun)	ability (noun)
lacking the power to perform	the quality of being able to perform; a quality that permits or facilitates achievement or accomplishment
lack of ability (especially mental ability) to do something	possession of the qualities (especially mental qualities) required to do something or get something done