Adjectives

(a)incapable(followed by `of') lacking capacity or ability“incapable of carrying a tune”, “he is incapable of understanding the matter”, “incapable of doing the work”
(a)incapable(followed by `of') not having the temperament or inclination for“simply incapable of lying”
(s)incapablenot being susceptible to or admitting of something (usually followed by `of')“incapable of solution”
(s)incapable, incompetent, unequal tonot meeting requirements“unequal to the demands put upon him”