The relative pronouns are:
关系代词有:

We use who and whom for people, and which for things.
我们用who和whom指代人,用which指代物品。

Or we can use that for people or things.
或者可以用that指人或物。

We use relative pronouns:
下列情况中我们使用关系代词:

• after a noun, to make it clear which person or thing we are talking about:
在名词后加关系代词,用于指明我们所谈论的人或物:

the house that Jack built

the woman who discovered radium

an eight-year-old boy who attempted to rob a sweet shop

• in relative clauses to tell us more about a person or thing:
在关系从句中提供关于某人或某物更多的信息:

My mother, who was born overseas, has always been a great traveller.

Lord Thompson, who is 76, has just retired.

We had fish and chips, which is my favourite meal.

But we do not use that as a subject in relative clauses.

We use whose as the possessive form of who:
我们用whose表明所有权:

This is George, whose brother went to school with me.

We sometimes use whom as the object of a verb or preposition:
有时用whom作为一个动词或介词的宾语:

This is George, whom you met at our house last year.

This is George’s brother, with whom I went to school.

But nowadays we normally use who:
但今天我们通常用who:

This is George, who you met at our house last year.

This is George’s brother, who I went to school with.

When whom or which have a preposition the preposition can come at the beginning of the clause...
当用whom和which有介词时,介词可以前置:

I had an uncle in Germany, from who[m] I inherited a bit of money.

We bought a chainsaw, with which we cut up all the wood.

… or at the end of the clause:
或者是放在句子最后:

I had an uncle in Germany who[m] I inherited a bit of money from.

We bought a chainsaw, which we cut all the wood up with.

We can use that at the beginning of the clause:
也可以将that放在句子开头:

I had an uncle in Germany, that I inherited a bit of money from.

We bought a chainsaw, that we cut all the wood up with.