同位語從句和定語從句很相似,相似之處在於都是修飾的前面一個名詞;但還是有區別的,區別主要在以下三方面:
定語從句同位語從區別：
1.從詞類上區別同位語從句前面的名詞只能是idea,fact,news,hope,belief,suggestion,proposal,Word,thought,doubt,truth,possibility,promise,order等有一定內涵的名詞。而定語從句的先行詞可以是名詞，代詞。主句的一部分或是整個主句。如:
The possibility that the majority of the labour force will work at home is often discussed. (同位語從句)
We are not looking into the question whether he is worth trusting.(同位語從句)
Word came that he had been abroad. (同位語從句)
Our team has won the game, which made us very happy.我們的'隊贏了,這讓我們很高興。(定語從句)
The doctor whom you are looking for is in the room.你找的那位醫生在房間裡面。(定語從句)
His mother did all she could to help him with his study.他媽媽盡她的最大努力幫助他的學習?(定語從句,代詞all作先行詞。)
2. 從性質上區別定語從句是從句對其先行詞的修飾或限制,屬於形容詞性從句的範疇;而同位語從句是從句對前面抽象名詞的進一步的說明和解釋,屬於名詞性從句的範疇。如:
The news that our team has won the game was true. 我們隊贏了那場比賽的訊息是真的?(同位語從句,補充說明news到底是一個什麼訊息。)
The news that he told me yesterday was true. 昨天他告訴我的那個訊息是真的。(定語從句,news在從句中作told的賓語。)
I made a promise that if anyone set me free I would make him very rich. 我許諾如果誰讓我自由,我就讓他非常富有。(同位語從句,補充說明promise到底是一個什麼諾言。)
The mother made a promise that pleased all her children. 媽媽做出了一個令她的孩子們高興的許諾?(定語從句,promise在從句中作pleased的主語。)
3. 從引導詞及其在句子中的成分上區別有些引導詞如how, whether, what可以引導同位語從句,但不能引導定語從句。如:
That question whether we need it has not been considered. 我們是否需要它這個問題還沒有考慮。(同位語從句)
I have no idea what has happened to him. 我不知道他發生了什麼事。(同位語從句)
引導詞that引導定語從句時,在從句中一般作主語或賓語(指物時還可以用which代替),並且作賓語時常常省略?that在同位語從句中僅起連線作用,不充當任何成分,並且不能省略,也不能用which來代替。如:
The order that we should send a few people to help the other groups was received yesterday. 我們應派幾個人去幫別的幾個小組的命令昨天收到了。(同位語從句,是對order的具體解釋,that雖不作成分,但不能省略。)
The order that we received yesterday was that we should send a few people to help the other groups. 我們昨天收到的命令是我們應該派幾個人去幫助別的幾個小組。(定語從句,是名詞order的修飾語,that在從句中作received的賓語,可以省略。)
同位語從句練習(含答案)：
1. The fact ____ she works hard is well known to us all.
A. that B. what C. why D. which
2. The fact ____ he was successful proves his ability.
A. that B. what C. which D. why
3. The news ____ he was kidnapped surprised us greatly.
A. what B. that C. why D. when
4. His suggestion ____ the meeting be delayed was turned down.
A. which B. that C./ D. it
5. I have no idea ____ he will start.
A. when B. that C. what D./
6. I’ve come from the government with a message ____ the meeting won't be held tomorrow.
A. if B. that C. whether D. which
7. The thought ____ he might fail in the exam worried him.
A. when B. which C. what D. that
8. The order ____ the prisoner be set free arrived too late.
A. which B. whether C. that D. what
9. The nurses are trying their best to reduce the patient's fear ____ he would die of the disease.
A. that B. as C. of which D. which
10. He often asked me the question ____ the work was worth doing.
A. whether B. where C. that D. when
11. Along with the letter was his promise ____ he would visit me this coming Christmas.
A. which B. that C. what D. whether
12. The other day, my brother drove his car down the street at ____ I thought was a dangerous speed.
A. as B. which C. what D. that
13. Luckily, we’d brought a road map without ____ we would have lost our way.
A. it B. that C. this D. which
14. There are signs ____ restaurants are becoming more popular with families.
A. that B. which C. in which D. whose
15. We can see the same signs ____ stand out throughout the city.
A. that B. which C. in which D. whose
Keys：
1-5 AABBA 6-10 BDCAA 11-15 BBDAA
