who，whom，whose和that作為定語從句的引導詞，稱為關系代詞。我們現在來看一下先行詞指人時，這四個關系代詞的使用問題。下面用句子合并的方法來分析。
一、定語從句用who或that做引導詞，在從句中做主語。
請分析下面兩個簡單句：句①The boy is called Jack.句②He broke the window.
把句②變為句①的定語從句，句①中的the boy做定語從句的先行詞。在句②中he指句①中提到的the boy也就是定語從句的先行詞，he在句中做主語，因此要用who和that引導定語從句，代替句②中的he，也就是說he就不能出現在定語從句中了。由此得到句③The boy who broke the window is called Jack.
注意：一般情況下定語從句要緊挨先行詞。
請把下面每組的兩句話合并為一句。
The person must pay for it./He lost the library book.
→The person who lost the library book must pay for it.
The boy is very clever./He is wearing the black jacket.
→The boy who is wearing the black jacket is very clever.
二、定語從句用who，whom或that做引導詞，在從句中做賓語。因為是做賓語，所以這些引導詞可以省略。
請分析下面兩個簡單句：句①Do you know the young man?句②We met him at the gate.
把句②變為句①的定語從句，句①中的the young man做定語從句的先行詞。在句②中him指句①中提到的the young man也就是定語從句的先行詞，him在句中做賓語，因此要用whom，that或who引導定語從句，代替句②中的him，也就是說him就不能出現在定語從句中了。由此得到句③Do you know the young man who/that/whom we met at the gate?(who/that/whom可以省略，句子可以寫作：Do you know the young man we met at the gate?)
請把下面每組的兩句話合并為一句。
Mr.Lee has come./You want to see him.
→Mr.Lee who/whom/that you want to see has come.
This is the girl.
He worked with her in the office./→This is the girl whom/that/who he worked with in the office.
三、定語從句用whose做引導詞，在從句中作定語表示“某些人的…”。
請分析下面兩個簡單句：句①The girl is staying at home today.句②Her mother is ill.
把句②變為句①的定語從句，句①中的the girl做定語從句的先行詞。在句②中her指句①中提到的the girl也就是定語從句的先行詞，her在句中做定語，因此要用whose引導定語從句，代替句②中的her，也就是說her就不能出現在定語從句中了。由此得到句③The girl whose mother is ill is staying at home today.
請把下面每組的兩句話合并為一句。
The boy is called LiLei./His parents were dead in the flood.
→The boy whose parents were dead is called LiLei
Mr.Wang is the policeman./His house caught fire last Sunday.
→Mr.Wang is the policeman whose house caught fire last Sunday.
鞏固練習：
一、用定語從句把下面兩句話合并為一句。
1.Let’s ask the man .He is reading the book over there.
2.The girl is Peter’s sister.We saw her yesterday.
3.This is Uncle Li.He mended computers for us.
4.I know the young man.You mean him.
5.I know the boy.His father is a scientist.
二、單項選擇
1.Have you seen the man _____ car was stolen just now?
A.its B.it’s C.whose D.which
2.On the bus I saw a student ____ I thought was your brother.
A.who B.whom C.which D.whoever
3.The foreigner ___ visited our school yesterday is from Canada.
A.that B.which C.whom D./
4.Here is the man ____ you are looking for.
A.which B.whom C.what D.where
答案：
一、
1.Let’s ask the man who/that is reading the book over there.
2.The girl that/whom/who we saw yesterday is Peter’s sister.
3.This is UncleLi who/that mended computers for us.
4.I know the young man whom/that/who you mean.
5.I know the boy whose father is a scientist.
二、1-4 C A A B
