Various ways to say “How come” in Chinese

The common expressions and their uses in sentences

怎么 (zěnme)

Subject + 怎么 + ……？
怎么 + Subject + ……？

This is the most direct and common way to say “how come” in Chinese. It’s versatile and can be used in both informal and slightly more formal contexts.

e.g.

怎么你还没去睡觉？(Zěnme nǐ hái méi qù shuìjiào?) How come you haven’t gone to sleep yet?

你怎么知道？(Nǐ zěnme zhīdào?) How come you know?

你们怎么出现这样的误会？(Nǐmen zěnme chūxiàn zhèyàng de wùhuì?) How could such a misunderstanding happen?

怎么回事 (zěnme huí shì)

……，怎么回事？
怎么回事，……？

Literally translating to “what’s the matter” or “what happened,” this phrase is used to ask about the reason behind an unexpected situation or event.

e.g.

怎么回事，为什么大家都在等？(Zěnme huí shì, wèishénme dàjiā dōu zài děng?) How come, why is everyone waiting?

这么快就结束了，怎么回事？(Zhème kuài jiù jiéshù le, zěnme huí shì?) How could it end so quickly?

怎么会 (zěnme huì)

(Subject +) 怎么会 + …… ？

This expression conveys a sense of surprise or disbelief, similar to “how could it be” or “how come.”

e.g.

怎么会下雨了？(Zěnme huì xiàyǔ le?) How come it’s raining?

怎么会有人不喜欢他？(Zěnme huì yǒu rén bù xǐhuān tā?) How could anyone not like him?

怎么会忘记带钥匙？(Zěnme huì wàngjì dài yàoshi?) How could I forget to bring the keys?

咋 (zǎ)

(Subject +) 咋 + …… ？

This is a colloquial and more informal version of “怎么 (zěnme),” often used in spoken language to express “how come” or “why.”

e.g.

咋还不走？(Zǎ hái bù zǒu?) How come you’re not leaving yet?

咋突然下雨了？(Zǎ tūrán xiàyǔ le?) How could it suddenly start raining?