unable vs able

unable and able both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unable	No	Yes	No	No
able	No	Yes	No	No

unable (adjective)	able (adjective)
(usually followed by `to') not having the necessary means or skill or know-how	(usually followed by `to') having the necessary means or skill or know-how or authority to do something
lacking in power or forcefulness	having inherent physical or mental ability or capacity
(usually followed by `to') lacking necessary physical or mental ability	have the skills and qualifications to do things well
	having a strong healthy body