"who"用于询问人的身份或特征，并可作为主语或谓语动词的补语。"whom"通常用作宾语，在正式的英语中用于代替或引用人。"whose"用于询问所属关系，表示某物归属于谁。
以下是一些口诀帮助你记忆：
- "Who is the person who helped me?"（帮助我的人是谁？）这里，“who”在从句中作主语。
- "The person whom I helped is my sister."（我帮助的那个人是我妹妹。）这里，“whom”在从句中作宾语。
- "This is the book whose cover is red."（这是封面是红色的书。）这里，“whose”表示所属关系，修饰先行词“book”。
1，如果先行词在从句中做主语，我们用who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。
Mr Smith who served in the army during WWII died at 89.
史密斯先生享年89岁，二战期间曾在军队服役。
Everything comes to him who waits.
功夫不负有心人。
Rights are won only by those who make their voices heard.
只有那些发出自己声音的人才能争取到应有权利。
2，如果先行词在从句中做宾语，我们用who或whom指代它：
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？
The old lady who/whom we met just now is Tom’s grandma.
我们刚才遇到的那位老太太是汤姆的奶奶。
但是，指代从句宾语，我们现在更喜欢用who，而且who或whom都可以省略。
3，如果先行词在从句中做介词宾语，我们可以用介词+whom指代它：
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。
I met some nice men, about whom I have heard nothing.
我遇到了一些好人，之前我没听说过他们。
介词+whom的句子显得很正式，一般人不会把介词放到whom前，而且如上所述，我们更多用who。
He is a man (who) I have the greatest admiration for.
I met some nice men, (who) I have heard nothing about.
some of, any of, one of, all of, both of, many of, few of等后面用whom：
It's a family of eight children, all of whom are studying music.
这是一个有八个孩子的家庭，他们都在学习音乐。
I made a lot of new friends there, some of whom are still in touch.
我在那里交了很多新朋友，其中有些人还保持着联系。
She brought with her three friends, none of whom I had ever met before.
她带来了她的三个朋友，我以前一个也没见过的。
4，如果先行词做从句中名词的定语，我们可以whose指代它：
The only creature on earth whose natural habitat is a zoo is the zookeeper.
地球上自然栖息地是动物园的唯一动物是动物园管理员。
Never go to a doctor whose office plants have died.
不要去房间里植物已经死了的医生那看病。
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。
注意先行词为物，只要在从句中做定语，也用whose指代！
The ship, whose engine had failed, is now safely under tow.
这艘船的引擎出了故障，现在已被安全地拖走了。
A house in Chicago has a roof whose actual drainage area is 1,000 square feet.
芝加哥有一所房子的屋顶际排水面积是1000平方英尺。
