形容词

1. 不能…的；无法…的
If you are unable to do something, it is impossible for you to do it, for example because you do not have the necessary skill or knowledge, or because you do not have enough time or money.

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

e.g. unable to get to town without a car
unable to obtain funds

2. lacking in power or forcefulness

e.g. an ineffectual ruler
like an unable phoenix in hot ashes

Synonym: ineffectiveineffectual