unable

Lacking in power or forcefulness.

“like an unable phoenix in hot ashes”

(usually followed by `to') lacking necessary physical or mental ability.

“dyslexics are unable to learn to read adequately”

“the sun was unable to melt enough snow”

(usually followed by `to') not having the necessary means or skill or know-how.

“unable to get to town without a car”

“unable to obtain funds”