modified
incapable, inefficient, inept, unskillful, inadequate, unfit, unskilled, unqualified, disqualified, bungling, inexpert, floundering, ineffectual, unsuitable, untrained, maladroit, unhandy, clumsy, awkward, uninitiated, raw, inexperienced, unequipped, unadapted, not equal to, amateurish; see also unable.
Antonyms able*, fit, qualified.