unable/ʌn'eɪbl/

a. not able to do sth

a. [不置于名词前] 不能的，不能胜任的：[unable to do sth] She was unable to sleep because of excitement. 她因兴奋而不能入睡。

构词un- + -able

常犯错误

✗ be unable of affording the house

✓ be unable to afford the house 买不起房子