How to translate “bad” depends on the meaning - Cchatty

How to translate “bad” depends on the meaning of “bad”

Use huài 坏, “bad,” for people only, much like the word “evil” in English: That man, bin-Laden, is really bad.

Bin-Laden nàge rén zhēn huài.
Bin-Laden 那个人真坏。

When combined with le 了，huài 坏 is used only with things, in which case it means “to go bad/spoiled/rotten”; “become wrecked/ruined”; “become useless; break down”:

My car has broken down.
Wǒde chēzi huàile.
我的车子坏了。

The bananas are spoiled.
Xiāngjiāo huài le.
香蕉坏了。

When something is “bad/not good,” use bùhǎo 不好: That movie is bad.

Nàge diànyǐng bùhǎo.
那个电影不好。

When talking about pain or illness, use lìhai 厉害, “bad” in the sense of “severe/serious”:

I have a bad headache.
Wǒde tóu téng de hěn lìhai.
我的头疼得很厉害。

That person has a bad cold.
Nàge rén gǎnmào de hěn lìhai.
那个人感冒得很厉害。