"Incapable" or "unable"?

Last class, we mentioned the words 'incapable' and 'unable'. Here go their definitions and examples so that their meaning is clearer.

INCAPABLE = not having the necessary ability, qualification, or strength to perform some specified act or function. Incompetent. 

As an administrator, he is simply incapable.
The children seem totally incapable of working by themselves.

Structure: INCAPABLE + OF + NOUN 
                INCAPABLE + OF + ING 

UNABLE = Not having the skill, time, knowledge, to do something. 

She was unable to hide her excitement.
Let us know if you are unable to come. 
We were unable to contact him at the time.

Structure: UNABLE + TO + INFINITIVE

I hope this helps!

See you!