不行【bù xíng】
1. won't do 2. be no good; not work 3. dying
[动短] 1、不可以 [形] 2、不中用 3、接近于死亡

你一个人去可不行,那样太危险了。
It is too dangerous for you to go there alone.

我喝酒真的不行,一喝就醉。
I have a small capacity for alcohol and get drunk easily.

病人已经不行了,准备后事吧。
There's no longer any possibility of curing the patient. You'd better start to make preparation for the funeral.