1、 定語從句在句中修飾某個名詞或代詞，被定語從句修飾的詞叫先行詞。定語從句需用下列關聯詞：
關系代詞 關系副詞
起連詞作用，本身做從句的主語、賓語、表語或定語 起連詞作用，本身在從句中作時間、地點或原因狀語
who, whom, that, whose, which, as when, where, why
2、 掌握以上關系代詞、關系副詞的含義及使用時，要特別注意以下幾點：
1） 指人時宜用who 的情況：
a. 當先行詞是 one, ones, anyone 或 those 時，關系代詞用 who。
Anyone who goes there will be punished.
b. 在there be 開頭的句子中。
There’s a beautiful girl who came to see you this morning.
c. 先行詞后有一個較長的定語。
I met a foreigner in the city last week who could speak Chinese well.
d. 在非限定性定語從句中。
She has a brother, who worked at that factory ten years ago.
2) 指物時宜用 that 的情況：
a. 當先行詞為 all, much, little, few, none, something, anything, everything, nothing 等不定代詞時。All that can be done has been done.
b. 當先行詞既指人又指物時。
He spoke of the men and the thing (that) he had seen abroad.
c. 當先行詞被序數詞或形容詞的最高級修飾時。
This is one of the best films that I have ever seen.
d. 當先行詞被 the very, the only, the last, any, every 等修飾時。
This is one of the very book that I am looking for.
e. 當先行詞是疑問詞 who, what, which 時。
Who that has such a home doesn’t love it?
f. 關系代詞在從句中作表語。
Mary is no longer the girl that she used to be.
3) 只能用 which 不能用 that 的情況。
a. 引導非限定性定語從句修飾某物或整個句子。
Bruce went towards the fire, which was still smoking.
Tom came back late, which made his parents very angry.
b. 關系代詞作介詞的賓語。This is the house in which Lu Xun once lived.
4) 關系代詞 as 和which都能引導非限定性定語從句代表整個句子的內容，as
引導的從句可位于句首或句末，which引導的定語從句則不能位于句首。
Which you know, he is a good man. (×)
As you know, he is a good man. (√)
6)關系副詞when, where, why其含義相當于on which, in which for which等，可以互換：
The day when /on which I met him first was May 1st.
I don’t know the reason why /for which he didn’t come.
7)whose指物時，可以與of which等結構互換，但應注意與冠詞的位置關系：
This is the book the cover of which / of which the cover / whose cover is blue.
8)有時可用代替關系副詞。在口語中常省略。
This is the reason (why / for which / that) he came late.
9)先行詞是專有名詞、整個句子或世界上獨一無二的物質名詞時，一般用非限定性定語從句修飾。The sun, which gives us light and heat, is very big.
10)在先行詞和定語從句之間有無逗號有時會引起名義的變化：
He said nothing that made her angry. 他沒說使她生氣的話。
He said nothing, which made her angry. 他一言不發，這使她很生氣。
3、 定語從句與強調結構
It is the place where they lived before.
It is in the place that they lived before.
第一個句子為定語從句，where指代the place，在定語從句中作狀語，第二個句子為強調結構，強調in the place, that沒有意義，把放回后面句子，句子意思完整。
Where is it that he found the lost watch? (強調句型，強調疑問副詞where.)
Where is the watch he found yesterday? (定語從句，that指代the watch.)
4、 定語從句中的先行詞
Is this book the one that you bought yesterday?
Is this the book that you bought yesterday?
第一個句子中，this book是主句的主語，the one是先行詞。在第二個句子中this是主句的主語，the book是先行詞。一定要避免出現：Is this book that you bought yesterday?
5、 定語從句與同位語從句
定語從句相當于形容詞，它對先行詞起修飾、描述或限制作用，而同位語從句則相當于名詞，對其前面的詞給予說明或作進一步解釋，即說明該詞所表示的具體內容。例如：
The news that we heard is not true. (定語從句)
The news that he won the prize is not true. （同位語從句）
另: 在“have no idea ＋從句”結構中，其從句都作idea的同位語。例如：
I have no idea when she will be back.
定語從句專項練習
1. I shall never forget those years ___________ I lived in the country with the farmers, _________ has a great effect on my life.
A. that; which B. when; which C. which; that D. when; who
2. Wilma became the first American woman to win three Olympic gold medals in track, _______ made her mother very proud.
A. it B. that C. which D. this
3. Can you tell me the name of the factory ____________ you visited last week?
A. what B. where C. / D. when
4. I don’t like the way ___________ you speak to her.
A. / B. in that C. which D. of which
5. The most important thing __________ we should pay attention to is the first thing ______ I have said.
A. which; that B. that; which C. which; which D. that; that
6. She spent the whole evening talking about the things and persons __________ none of us has ever heard of.
A. which B. who C. whom D. that
7. He never reads anything _________ is not worth reading.
A. which B. as C. who D. that
8. I have bought such a watch ___________ was advertised on TV.
A. that B. which C. as D. it
9. _______ was expected, he failed in the exam.
A. That B. As C. Which D. It
10. I can never forget the day _________ we worked together and the day ________ we spent together.
A. when; which B. which; when C. what; that D. on which; when
11. The children climbed up the hill, _________ they picnicked.
A. on its top B. on the top of it C. on whose top D. on the top of that
12. I still remember the day __________ I first came to the college.
A. on which B. in which C. at which D. which
13. They will never forget the day _________ they got married.
A. that B. which C. in which D. when
14. He makes good use of the time _________ he can spare.
A. when B. that C. in that D. in which
15. The factory ___________ his mother works is in the east of the city.
A. that B. which C. on which D. where
16. The place _________ interested me most was the Children’s Palace.
A. which B. where C. what D. in which
17. That is the reason ________ he wasn’t here yesterday.
A. why B. which C. on which D. in which
18. That is the reason ________ he can’t say.
A. why B. that C. what D. in which
19. You have no idea _________ worried I was.
A. how B. however C. that D. where
高考試題選練
1. The film brought the hours back to me __________ I was taken good care of in that faraway village.
A. until B. that C. when D. where
2. John said he’d been working in the office for an hour, _________ was true.
A. he B. this C. which D. who
3. Recently I bought an ancient Chinese vase, _________ was very reasonable.
A. which price B. the price of which C. its price D. the price of whose
4. Have you seen the film “Titanic”, ________ leading actor is world famous.
A. is B. it’s C. whose D. which
5. The famous basketball star, _______ tried to make a comeback, attracted a lot of attention.
A. where B. when C. which D. who
6. The English play _______ my students acted at the New Year’s party was a great success.
A. for which B. at which C. in which D. on which
7. ________ is reported in the newspapers, talks between the two countries are making progress.
A. It B. As C. That D. What
8. I work in a business ________ almost everyone is waiting for a great chance.
A. how B. which C. where D. that
9. Anyway, that evening, _________ I’ll tell you more about later, I ended up staying at Rachel’s place.
A. when B. where C. what D. which
10. There were dirty marks on her trousers ________ she had wiped her hands.
A. where B. which C. when D. that