【考情分析】
名詞性從句是歷年高考的重點和難點也是熱點。名詞性從句相當於名詞，可用作主句的主語、表語、賓語和同位語。因此，名詞性從句分爲主語從句、表語從句、賓語從句和同位從句。引導名詞性從句的連接詞有: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;連接副詞:when, where, why, how，有詞義，在從句中擔任成分，作狀語;連接詞:that, whether, if, as if，if (whether), as if雖有詞義，但在從句中不擔任成分;that 無詞義，在從句中不擔任成分，有時可省略。
今後對名詞性從句的考查仍將集中在關聯詞的選用上，特別石堆what引導的名詞性從句的考查。名詞性從句與其他從句的混合考查將在今後高考中佔據一席之地。易混句型的辨析，比如it作形式主語，主語從句後置的句型與強調句型的辨析將仍作爲高考考查的重點。
【知識點歸納】
名詞性從句的用法
在句子中起名詞作用的句子叫名詞從句 (Noun Clauses)。 名詞從句的功能相當於名詞詞組, 它在複合句中能擔任主語、賓語、表語、同位語、介詞賓語等，因此根據它在句中不同的語法功能，名詞從句又可分別稱爲主語從句、賓語從句、表語從句和同位語從句。
一、引導名詞性從句的連接詞
引導名詞性從句的連接詞可分爲三類:連詞:that(無任何詞意);whether, if(均表示“是否”表明從句內容的不確定性);as if ,as though(均表示“好像”，“似乎”)。
以上在從句中均不充當任何成分
連接代詞:what, whatever, who, whoever, whom, whose, which. Whichever, whomever
連接副詞:when, where, how, why
不可省略的連詞:
1. 介詞後的連詞
2. 引導主語從句和同位語從句的連詞不可省略。
That she was chosen made us very happy.
We heard the news that our team had won.
比較:
Whether與if 均爲"是否"的意思。 但在下列情況下，whether 不能被if 取代:
1. Whether引導主語從句並在句首;
2. 引導表語從句
3. Whether從句作介詞賓語;
4. 從句後有"or not"
Whether he will come is not clear.
大部分連接詞引導的主語從句都可以置於句末，用 it充當形式主語。
It is not important who will go.
It is still unknown which team will win the match.
二、具體分類
1.主語從句
作句子主語的從句叫主語從句。主語從句通常由從屬連詞that，whether，if和連接代詞what，who，which，whatever，whoever以及連接副詞how，when，where，why等詞引導。that在句中無詞義，只起連接作用;連接代詞和連接副詞在句中既保留自己的疑問含義、又起連接作用，在從句中充當從句的成分。例如:
What he wants to tell us is not clear. 他要跟我們說什麼，還不清楚。
Who will win the match is still unknown. 誰能贏得這場比賽還不得而知。
It is known to us how he became a writer. 我們都知道他是如何成爲一名作家的。
Where the English evening will be held has not yet been announced. 英語晚會將在哪裏舉行，還沒有宣佈。
【典例1】(2009·上海卷)It is immediately clear ____ the financial crisis will soon be over.
A. since B. what C. when D. whether
【答案】D
【解析】考查主語從句的用法。該句的意思時:經濟危機是否會很快結束是很明顯的事情。“是否”用whether表示，不能選when是因爲從句中由soon這一實踐狀語。
【典例2】(2008·山東卷)_____ was most important to her, she told me, was her family.
A. It B. This C. What D. As
【答案】C
【解析】she told me是插入語，可刪除。what引導主語從句，在從句中充當主語。
有時爲避免句子頭重腳輕，常用形式主語it代替主語從句作形式主語放於句首，而把主語從句置於句末。主語從句後的謂語動詞一般用單數形式。常用句型如下:
(1)It + be + 名詞 + that從句
(2)It + be + 形容詞 + that從句
(3)It + be + 動詞的過去分詞 + that從句
(4)It + 不及物動詞 + that 從句
另注意在主語從句中用來表示驚奇、不相信、惋惜、理應如此等語氣時，謂語動詞要用虛擬語氣“(should) +do”，常用的句型有:
It is necessary (important, natural, strange, etc.) that …
It is a pity (a shame, no wonder, etc.) that…
It is suggested (requested, proposed, desired, etc.) that…
【典例】(2009·天津卷)It is obvious to the students ______ they should get well prepared for their future.
A. as B. which C. whether D. that
【答案】D
【解析】考查名詞性從句。本空格處應是一個主語從句的引導詞，因該主語從句不缺成分，且句意完整，故應用不作任何成分的連詞that。
2.賓語從句
名詞句用作賓語的從句叫賓語從句。引導賓語從句的關聯詞與引導主語從句表語從句的關聯詞大致一樣，在句中可以作謂語動詞或介詞及非謂語動詞的賓語。
(1) 由連接詞that引導的賓語從句
由連接詞that引導賓語從句時，that在句中不擔任任何成分，在口語或非正式的文體中常被省去，但如從句是並列句時,第二個分句前的that不可省。例如:
He has told me that he will go to Shanghai tomorrow. 他已經告訴我他明天要去上海。
We must never think (that) we are good in everything while others are good in nothing. 我們決不能認爲自己什麼都好，別人什麼都不好。
注意:在demand，order，suggest，decide，insist，desire，request，command等表示要求、命令、建議、決定等意義的動詞後，賓語從句常用“(should)+ 動詞原形”。例如:
I insist that she (should) do her work alone. 我堅持要她自己工作。
The commander ordered that troops (should) set off at once. 司令員命令部隊馬上出發。
(2)用who，whom, which, whose, what, when, where, why, how, whoever, whatever, whichever等關聯詞引導的賓語從句相當於特殊疑問句，應注意句子語序要用陳述語序。例如:
I want to know what he has told you. 我想知道他告訴了你什麼。
She always thinks of how she can work well. 她總是在想怎樣能把工作做好。
She will give whoever needs help a warm support. 凡需要幫助的人，她都會給予熱情的支持。
【典例1】(2008·北京卷)The companies are working together to create _______ they hope will be the best means of transport in the 21st century.
A. which B. that C. what D. who
【答案】C
【解析】create後爲賓語從句，從句中they hope是插入語，可刪除。因爲從句中缺少主語，所以用what引導該從句。
【典例2】(2009· 全國卷Ⅰ) Could I speak to is in charge of International Sales please?
A. who B. what C. whoever D. whatever
【答案】C
【解析】 考查名詞性從句。題幹中介詞to後面爲賓語從句，從句中缺少主語，因此填whoever。
(3)用whether或if引導的賓語從句，其主語和謂語的順序也不能顛倒，仍保持陳述句語序。此外，whether與if 在作“是否”的意思講時在下列情況下一般只能用whether，不用if:
a. 引導主語從句並在句首時;b. 引導表語從句時;c . 引導從句作介詞賓語時;d. 從句後有“or not”時;e. 後接動詞不定式時。例如:
Whether there is life on the moon is an interesting question. 月球上有沒有生命是個有趣的問題。
The question is whether she should have a low opinion of the test?
Everything depends on whether we have enough money. 一切要看我們是否有足夠的錢。
I wonder whether he will come or not. 我想知道他來還是不來。
Can you tell me whether to go or to stay? 你能否告訴我是去還是留?
(4)注意賓語從句中的時態呼應，當主句動詞是現在時，從句根據自身的句子情況，而使用
不同時態。例如:
he studies English every day. (從句用一般現在時)
he studied English last term. (從句用一般過去時)
I know (that) he will study English next year. (從句用一般將來時)
he has studied English since 1998. (從句用現在完成時)
當主句動詞是過去時態(could, would除外)，從句則要用相應的過去時態，如一般過去時，過去進行時，過去將來時等;當從句表示的是客觀真理，科學原理，自然現象，則從句仍用現在時態。例如:
The teacher told us that Tom had left us for America.
(5)think, believe, imagine, suppose等等動詞引起的否定性賓語從句中，要把上述主句中的動詞變爲否定式。即將從句中的否定形式移到主句中。例如:
We don’t think you are here. 我們認爲你不在這。
I don’t believe he will do so. 我相信他不會這樣做。
3.表語從句
在句中作表語的從句叫表語從句。引導表語從句的關聯詞與引導主語從句的關聯詞大致一樣，表語從句位於連繫動詞後，有時用as if引導。其基本結構爲:主語 + 系動詞 + that從句。例如:
The fact is that we have lost the game. 事實是我們已經輸了這場比賽。
That’s just what I want. 這正是我想要的。
This is where our problem lies. 這就是我們的問題所在。
That is why he didn’t come to the meeting. 那就是他爲什麼不到會的`原因。
It looks as if it is going to rain. 看上去天要下雨了。
需要注意的，當主語是reason時，表語從句要用that引導而不是because。例如:
The reason why he was late was that he missed the train by one minute this morning .
【提撥】whether 可引導表語從句，但與之同義的if卻通常不用於引導表語從句。
【典例1】 (2009·山東卷)The little girl who got lost decided to remain ________she was and wait tor her mother.
A. where B. what C. how D. who
【答案】A
【解析】remain是系動詞，後加表語從句，由句意可知，從句缺地點狀語，所以選A。
【典例2】(2008·天津卷)The last time we had grat fun was _______ we were visiting the Water Park.
A. where B. how C. when D. why
【答案】C
【解析】was後爲表語從句，此處when與the last time相呼應，根據句意可排除其他選項。
4. 同位語從句
同位語從句說明其前面的名詞的具體內容。同位語從句通常由that引導，可用於同位語從句的名詞有advice，demand，doubt，fact，hope，idea，information，message，news，order，problem，promise，question，request，suggestion，truth，wish，word等。例如:
The news that we won the game is exciting. 我們贏得這場比賽的消息令人激動。
I have no idea when he will come back home. 我不知道他什麼時候回來。
The thought came to him that Mary had probably fallen ill. 他想到可能瑪麗生病了。
【典例】(2009· 重慶卷) We should consider the students’ request ________ the school library provide more books on popular science.
A. that B. when C. which D. where
【答案】A
【解析】考查名詞性從句。根據題意知，空格處是同位語從句的引導詞，修飾中心名詞request，且在句子中不充當成分，故用that。這句話的意思是我們應該考慮學生的這個要求，即學校圖書館應該多提供一些大衆科學方面的書籍。
三、對比與用法
1.同位語從句和定語從句的區別:
that作爲關係代詞，可以引導定語從句，充當句子成分，在從句中作賓語時可以省略; that引導同位語從句時，起連詞的作用，沒有實際意義，不充當句子成分，一般不能省略。
試比較下面兩個例句:
I had no idea that you were here.(that引導同位語從句，不能省略)
Have you got the idea(that)this book gives you of life in ancient Greece?(that引導定語從句，作賓語，可以省略)
-從句作主語通常用it作先行詞，而將that-從句置於句末。
用it作形式主語的that-從句有以下四種不同的搭配關係:
a. It + be +形容詞+ that-從句
It is necessary that… 有必要……
It is important that… 重要的是……
It is obvious that… 很明顯……
b. It + be + -ed 分詞+ that-從句
It is believed that… 人們相信……
It is known to all that… 從所周知……
It has been decided that… 已決定……
c. It + be +名詞+ that-從句
It is common knowledge that… ……是常識
It is a surprise that… 令人驚奇的是……
It is a fact that… 事實是……
d. It +不及物動詞+ that-分句
It appears that… 似乎……
It happens that… 碰巧……
It occurred to me that… 我突然想起……
It is quite clear that the whole project is doomed to failure.
很清楚，整個計劃註定要失敗。
It's a pity that you should have to leave.
你非走不可真是件憾事。
3.否定轉移
(1) 將think, believe, suppose, expect, fancy, imagine等動詞後面賓語從句的否定詞轉移到主句中，即主句的謂語動詞用否定式，而從句的謂語動詞用肯定式。
I don't think I know you. 我想我並不認識你。
I don' t believe he will come. 我相信他不回來。
注意:若謂語動詞爲hope,賓語從句中的否定詞不能轉移。
I hope you weren't ill. 我想你沒有生病吧。
(2)將seem, appear 等後的從句的否定轉移到前面。
It doesn't seem that they know where to go.
看來他們不知道往哪去。
It doesn't appear that we'll have a sunny day tomorrow.
看來我們明天不會碰上好天氣。
【備考策略】
考生對於名詞性從句的複習和應試關鍵要把握每個引導詞的意義，因爲在對於名詞性從句的考查中，引導詞在句子中都起作用，有意義，因此在分析句子結構，對比辨別名詞性從句、狀語從句、強調句式後，最後還是要選擇引導詞;另外還要注意以下幾點:
引導詞的考查，尤其位於介詞後引導的賓語從句以及引導名詞性從句時的雙重作用。
her和if 的區別，尤其注意他們的不同之處。
3.名詞性從句和其它從句的兼容結構測試。
4.句子語序和時態。
具體說:
1.掌握名詞性從句的分類功能
名詞性從句根據其在主句的功能作用又可分爲主語從句、賓語從句、表語從句和同位語從句。
(1) 若從句在句中作主語爲主語從句
(2) 若從句在句中作賓語爲賓語從句
(3)若從句在句中作表語爲表語從句
(4) 若從句在句中作同位語爲同位語從句
2.掌握連詞的含義及分類
絕大多數名詞性從句的連詞都有其實在意義，稱爲有義連詞，如what表“……的內容”，when表“……的時間”，where表“……的地點”，why表“……的原因”，how表“如何;怎樣”，who表“誰”，if, whether表“是否”;沒有實在意義的連詞叫無義連詞，無義連詞只有that一個。
3.掌握名詞性從句的語序
名詞性從句用陳述語序。
4.掌握名詞性從句和其它從句之間的關係
有些連詞除引導名詞性從句外還可引導其它從句，應掌握它們之間的關係。
(1) if ,whether表"是否"時引導名詞性從句;if表“如果”時引導條件狀語從句;whether表“無論是否;不管是否”時引導讓步狀語從句。
(2) when表“……的時間”，where表“……的地方”時引導名詞從句;when表“當……的時候”引導時間狀語從句，where表“……的地方”，且修飾行爲動詞時，引導地點狀語從句;when, where從句作定語修飾先行詞時引導定語從句。
【專題突破】
高考中考查名詞性從句時，經常考查連接詞的選用。解題時應先判斷從句的類型，然後判斷從句是否缺少成分以及意義是否完整，最後根據引導名詞性從句的連詞的特點確定特定的連接詞。要求學生在做題中要注意如下幾點:
1.分析結構，辨析名詞性從句和狀語從句;
2.理解句意，正確區別引導詞;
3.按照句意，出現那個引導詞意思，便選擇那個引導詞。
【專題鞏固】
1. A warm thought suddenly came to me _______I might use the pocket money to buy some flowers for my mother’s birthday .
A. if B. when C. that D. which
2. See the flag on top of the building ? That was _______ we did this morning.
A when B. which C. where D. what
3. The government has announced that a modern city will be set up in _______is still a wasteland now.
A. what B. which C. that D. where
people wrote articles on _______Liu Xiang had failed to compete in the event .
A. why B. what C. who D. that
couple are spending their holiday on _______is described as one of the most beautiful islands.
A. that B. what C. which D. where
book is meant to _______needs it .
A. who B. whoever C. whomever D. whom
7. In his speech, Premier Wen Jiabao points out that creativity is_______it takes to keep a nation highly competitive.
A. how B. what C. which D. that
experience of the Chinese nation attests to a truth_______ a nation loses in times of disaster will be made up for by her progress.
A. that what B. what C. that D. what that
9._______has recently been done to provide more buses for the people ,a shortage of public vehicles remains a serious problem .
A. That B. What C. In spite of what D. Though what
10. _______is certain is _______prevention is more important than treatment.
A. It; that B. What; that C. As; what D. What; what
11. Nobody would stand out admitting the fact, for some reason, _______they lost the game.
A. that B. which C. what D. why
12.-The patient looks much better. _______is it that has made him_______he is today?
-Perhaps the special medicine and his family’s patient care.
; that ; that ; what ; which
13. After three hours’ climbing , they reached _______ they thought was the place they’d been dreaming of .
h e
14. A plan has been put forward _______more graduates should go to work in the country
A. when B. that C. whether D. how
is pretty well understood _______controls the flow of carbon dioxide in and out the atmosphere today.
A. that B. when C. what D. how
16.(2009· 湖南卷) She is very dear to us. We have been prepared to do _______it takes to save her life.
A. whichever B. however C. whatever D. whoever
17.(2009·陝西卷) The how- to book can be of help to _______wants to do the job.
A. who B. whomever C. no matter who D. whoever
18.(2009· 安徽卷) A good friend of mine from I was born showed up at my home right before I left for Beijing.
A. how B. whom C. when D. which
19.(2009·江蘇卷)Many young people in the West are expected to leave_______could be life’s most important decision-marriage-almost entirely up to luck.
A. as B. that C. which D. what
20. (2009·浙江卷)-Is there any possibility ______ you could pick me up at the airport?
-No problem.
A. when B. that C. whether D. what
【參考答案及解析】
1. C 句意:我腦海中突然出現一個溫情的念頭，用我的零花錢給媽媽買些鮮花作爲她的生日禮物。本題考察名詞性從句用法。I might use the pocket money to buy some flowers for my mother’s birthday .做A warm thought 的同位語從句。中間被suddenly came to me隔開，增加了試題難度。此外，部分考生由於對同位語從句和定語從句不分，故錯選D爲答案。
2. D 表語從句中缺did的賓語。
3. A “_______is still a wasteland now .”做介詞in的賓語從句，從句中缺主語句意爲:政府已經宣佈一座現代化的城市將在這片現在仍是廢墟的地方建成。
4. A“_______Liu Xiang had failed to compete in the event.”做介詞on的賓語，賓語從句中不缺主幹，故排除B和C。另外that不引導介詞的賓語從句(固定搭配除外)，所以排除D。
5. B “_______is described as one of the most beautiful islands .”賓語從句，從句中缺少主語，
6. B whoever在賓語從句中做主語，部分學生，因爲只看到介詞to，誤認爲要添whomever做介詞的賓語。
7. B “_______it takes to keep a nation highly competitive.”做表語從句，從句中缺少takes的賓語，構成 it takes sth to do sth 結構。
8. A本題句子結構比較複雜，“_______ a nation loses in times of disaster will be made up for by her progress”做a truth的同位語從句，同位語從句中_______ a nation loses in times of disaster爲主語從句。本句共有兩個從句，故有兩個引導詞。句意爲“中華民族的經驗證明了一個真理，即，一個民族在災難中失去的，必將從民族的進步中得到補償。
9. C “_______has recently been done to provide more buses for the people”在句中做讓步狀語,而D. Though what錯誤, 因爲, 一個單一的從句不能用兩個連詞引導.句意: 儘管在爲人們提供更多公交車這件事上, 投入了很多, 但是公交工具的缺乏, 仍然是個問題.
10.B “_______is certain”在句中做主語,主語從句缺少一個主語,需要用What; “_______prevention is more important than treatment .”系表語從句,句意與結構完整,只有that,可以這樣用。
11.A“_______ they lost the game.”在句子中做the fact 的同位語從句,從句意思結構完整,結構完整。
12. C先將句子結構理清楚，it is _______that has made him _______he is today 就可以判斷，第一個空是考察強調句型的特殊疑問形式;第二個空則是表語從句，表語從句中缺少he is的表語。句意:病人好多了，是什麼使得他成爲現在這個樣子。
13. A考生誤以爲是地點狀語從句，誤選e。而reached是及物動詞，後邊接的是賓語從句，賓語從句除去插入語they thought，應該缺主語。
14.B 考察同位語從句，表達A plan的具體內容，has been put forward將名詞與從句隔開，加大了難度。
15.C 主要測試主語從句。分析句子結構可知:句子屬於形式主語格式;另外主句中缺少主語。雙重作用的引導詞只能是what。例如:It is still doubtful what he said at the meeting yesterday。昨天他在會上說的話仍然值得懷疑。
16.C 名詞性從句的引導詞。句意爲:她對我們來說是非常寶貴，我們已經準備好做一切來拯救她的生命。
17.D 此處從句作介詞to的賓語，是名詞性從句，引導詞作從句的主語，指人，意思是:無論是誰，選D。
18.C 考查名詞性從句，介詞from後除了接代詞或名詞作賓語外，還可接介詞短語或副詞短語作賓語;由後面“I was born”可以推測from後面可以指時間，也可以指地點，再由所給的選項可得出答案。
19.D 考查名詞性從句。賓語從句中缺少主語，因此選what。
20. B考查同位語從句。此處是由what引導的同位語從句，表示“你有沒有可能來機場接我?”。所以選B項。
