who
英 [huː]   美 [huː]  
pron.
谁;(询问姓名、身份或职务)什么人;表示所指的人;进一步提供有关某人的信息

例句

Who is that woman?

那个女的是谁？

I wonder who that letter was from.

我不知道是谁来的信。

The people who called yesterday want to buy the house.

昨天打电话来的人想买这座房子。

Who are you to tell me I can't park here?

你凭什么不让我在这儿停车？