如果先行词在从句中做主语，用who指代它；如果先行词在从句中做宾语，用who或whom指代它；如果先行词在从句中做介词宾语，可以用介词+whom指代它；如果先行词做从句中名词的定语，可以whose指代它。

The boy who is running ahead of others is from Class 3.

跑在最前面的那个男孩是三班的。

She spoke to the man who works in the bank.

她和在银行工作的人谈过了。

She's the girl who/whom I told you about.

她就是我跟你说过的那个女孩。

Do you know the young man who/whom Mary is talking to?

你认识和玛丽谈话的那个年轻人吗？

These new neighbours, to whom I was introduced yesterday, have come here from Singapore.

我昨天经人介绍认识这些新邻居是从新加坡来的。

He is a man for whom I have the greatest admiration.

他是我极为钦佩的一个人。

She was a famous model whose looks were her riches.

她是一位著名的模特，容貌是她的财富。