【編者按】名詞性從句相當于名詞，可分別作主句的主語、表語、賓語和同位語。因此，名詞性從句廳分為主語從句、表語從句、賓語從句和同位從句。
(一)引導名詞性從句的連接詞
1、連接代詞：who, whose, whom, what, which。有詞義，在從句中擔任成分，如主語、表語、賓語、或定語等。
2、連接副詞：when, where, why, how。有詞義，在從句中擔任成分，作狀語。
3、連接詞：that, whether, if, as if。that 無詞義，在從句中不擔任成分，有時可省略;if (whether), as if雖有詞義，但在從句中不擔任成分。
注意：連接代詞與連接副詞在句中不再是疑問句，因而從句中謂語不用疑問式。連接代詞與連接副詞在從句充當句子成分，連接詞whether 和if(是否)，as if(好象)在從句中不充當句子成分，只起連接作用。根據(jù)句義，如果連接代詞與連接副詞，whether、if 和as if都用不上時，才用that作連接詞(that本身無任何含義)。
(二)主語從句
1、主語從句在復合句作主語。
e.g. Who will go is not important.
2、用it作形式主語，主語從句放在句末。
e.g. It doesn't matter so much whether you will come or not.
3、that引導主語從句時，不能省略。
e.g. That he suddenly fell ill last week made us surprised.
(三)表語從句
1、表語從句在復合句中作表語，位于系動詞之后。
e.g. The question was who could go there.
2、引導表語從句的連接詞that有時可省去。
e.g. My idea is (that) we can get more comrades to help in the work.
(四)賓語從句
1、賓語從句在復合句中作賓語。引導賓語從句的連詞that一般可省略。
e.g. I hope (that) everything is all right.
2、介詞之后的賓語從句，不可用which或if連接，要分別用what或 whether。
e.g. I'm interested in whether you've finished the work..
I'm interested in what you've said.
3、whether與if都可以引導賓語從句，�？苫Q。但下面情況不能互換。
①賓語從句是否定句時，只用if，不用whether。
e.g. I wonder if it doesn't rain.
②用if 會引起誤解，就要用whether。
e.g. Please let me know whether you want to go.(此句如果把whether改成if，容易當成條件句理解)
③賓語從句中的whether 與or not直接連用，就不能換成if;不直接連用，可換。
e.g. I don't know whether or not the report is true.
I don't know whether/ if the report is true or not.
④介詞后的賓語從句要用whether引導。whether 可與不定式連用。whether也可引導主語從句、表語從句、同位語從句，還可引導讓步狀語從句，以上均不能換成if。但引導條件從句時，只能用if，而不能用whether。
e.g. It depends on whether we have enough time.
They don't know whether to go there.
Please come to see me if you have time.
(五)同位語從句
同位語從句在句中作某一名詞的同位語，一般位于該名詞(如：news, fact, idea, suggestion, promise等)之后，說明該名詞的具體內(nèi)容。
e.g. I have no idea when he will be back.
The fact that he had not said anything surprised everybody.
練習：名詞性從句
一、判斷下列各句哪句含有名詞性從句，并指出是什么從句：
1. China is no longer what it used to be.
2. The truth that the earth turn around the sun is known to all.
3. It was snowing when he arrived at the station.
4. How he persuaded the manager to change the plan is interesting to us all.
5. The news that they had won the game soon spread over the whole school.
6. The news that you told me yesterday was really disappointing.
7. That is where Lu Xun used to live.
8. He spoke as if he understood what he was talking about.
9. Do you remember the teacher who taught us English at middle school?
10. I wonder why she refused my invitation.
二、用適當?shù)倪B詞填空：
1. I can't decide ____________ dictionary I should buy.
2. That's ____________ he refused my invitation.
3. I am very interested in ____________ he has improved his pronunciation in such a short time.
4. ____________ we need is more time.
5. The fact ____________ she had not said anything at the meeting surprised everybody.
6. ____________ and ____________ they will meet has not been decided yet.
7. Please tell me ____________ you are waiting for.
8. Is that ____________ you are looking for?
9. Would you please tell me ____________ the nearest post office is?
10. I don't know ____________ he will agree to the plan or not.
三、選擇填空：
1. Do you see _____ I mean?
A. that B./ C. how D. what
2. Tell me_____ is on your mind.
A. that B. what C. which D. why
3. We must stick to _____ we have agreed on.
A. what B. that C. / D. how
4. Let me see _____.
A. that can I repair the radio B. whether -I can repair the radio
C. I can repair the radio D. whether can I repair the radio
5. Keep in mind _____.
A. that the teacher said B. what did the teacher say
C. that did the teacher say D. what the teacher said
6. Could you advise me _____?
A. which book should I read first B. what book should I read first
C. that book 1 should read first D. which book I should read first
7. He was criticized for _____.
A. he had done it B. what he had done C. what had he done D. that he had done it
8. Would you kindly tell me _____?
A. how can I get to the Beijing Railway Station
B. how I can get to the Beijing Railway Station
C. where can I get to the Beijing Railway Station
D. whether can I get to the Beijing Railway Station
9. Mrs. Smith was very much impressed by _____.
A. what had she seen in China B. that she had seen in China
C. what she had seen in China D. which had she seen in China
10. We took it for granted ___
A. that they were not coming B. that were they not coming
C. they were coming not D. were they not coining
11. I really don't know _____
A. I should do next B. what should I do next
C. what I should do next D. how I should do next
12. I'm afraid _____.
A. the little girl will have to be operated on
B. that will the little girl have to operate on
C. the little girl will have to operate on
D. that will the little girl have to be operated on
13. She walked up to _____ .
A. where did I stand B. where I stood
C. I stood there D. where I stood there
14. Can you tell me _____?
A. who is that gentleman B. that gentleman is who
C. who that gentleman is D. whom .is that gentleman
15. We'll give you _____.
A. that do you need B. what do you need
C. whatever you need D. whether do you need
16. They want us to know _____ to help us.
A. what can they B. what they can C. how they can D. how can they
17. We must put _____ into practice.
A. what we have learned B. that we have learned
C. that have we learned D. what have we learned
18. Did she say anything about _____?
本文來自：逍遙右腦記憶 http://yy-art.cn/gaozhong/236335.html
相關(guān)閱讀：高中英語作文祝賀信怎么寫