一、主語從句的概念與類型
主語從句在復合句中作主句的主語,引導主語從句的詞有從屬連詞that, whether以及連接代詞who, what, which, whoever, whatever, whichever和連接副詞when, where, why, how等.例如:
That she was chosen made us very happy.
她當選了使我們很高興.
What caused the accident is a complete mystery.
是什麼導致了這次事故還完全是一個謎.
Whether she will come or not is still a question.
她是否來還是一個問題.
Which team will win the match is still unknown.
哪個隊會贏得這場比賽還不知道.
Whoever comes to the party will receive a present.
參加聚會的每一個人都將收到一份禮物.
When they will start has not been decided yet.
他們何時出發還沒決定.
注意:上述例句中的主語從句都是放在句首,但有時為了使句子結構平衡,避免"頭重腳輕",常用it作形式主語,而把從句放在後面.例如:
It is a pity that she has made such a mistake.
她犯了這樣一個錯誤,真是遺憾.
It depends on the climate whether they are going shopping today.
他們是否今天去購物還得看天氣情況.
這樣就構成了下面一些常用句型:
1)It is + adj. / n. +從句
It is a pity/shame that...遺憾的是……
It is possible that...很可能……
It is unlikely that...不可能……
2)It +不及物動詞+從句
It seems/appears that...似乎……
It happened that...碰巧……
3)It + be +過去分詞+從句
It is said that...據說……
It is known to all that...眾所周知……
It is reported that...據報道……
It is believed that...據信……;人們相信……
It is suggested that...有人建議……
It must be pointed out that...必須指出……
It has been proved that...已證明…….例如:
It is believed that at least a score of buildings were damaged or destroyed.據信,至少有二十座樓房遭到破壞或徹底毀掉.
It is suggested that the meeting should be put off.有人建議會議延期召開.
It's reported that three people were killed in the accident and five were hurt badly.據報道,事故中三人喪生,五人重傷.
It is known to all that Taiwan is an inseparable part of China.眾所周知,台灣是中國不可分割的一部分.
[鞏固練習]
1. Does _______ matter if he can't finish the job on time?
A. this B. that C. he D. it
2. It worried her a bit _______ her hair was turning grey.
A. which B. that C. if D. for
3. _______ is a fact that English is being accepted as an international language.
A. There B. This C. That D. It
二、學習主語從句應該注意的幾個問題
1)引導詞that與what
what既有引導主語從句的作用,同時又在從句中作句子成分(主語、賓語、表語等).這時what相當於all that/everything that...,常譯成"所……的(東西、事情、話等.)";而that只起連接作用,本身無實際意義,在從句中也不擔當任何句子成分.但that引導的主語從句放在句首時,不能省略that.例如:
What is done can't be undone.
(諺語)已成定局,無可挽回.
What we can't get seems better than what we have.
我們得不到的東西似乎比已得到的要好.
That we should work out a plan to deal with the present serious situation is important.
我們應該制定一項計劃來應付目前嚴峻的形勢,這一點非常重要.
That a new teacher will come to teach us geography is true.
一位新老師將來教我們地理,這是真的.
[鞏固練習]
4. _______ what they told me really true?
A. Has B. Is C. Does D. Have
5. It matters little _______ a man dies, but _______ matters much is _______ he lives.
A. how; what; how B. how; it; how C. why; it; why D. that; what; that
6. _______ she couldn't understand was _______ fewer and fewer students showed interest in her lessons.
A. What; why B. That; what C. What; because D. Why; that
7. It is pretty well understood _______ controls the flow of carbon dioxide in and out the atmosphere today.
A. that B. when C. what D. how
8. _______ fashion differs from country to country may reflect the cultural differences from one aspect.
A. What B. That C. This D. Which
9. -What made her parents so angry?
- _______ she had failed in the examination.
A. As B. Because C. Since D. That
2)引導詞if和whether
if和whether引導動詞後的賓語從句時一般可通用,但介詞後的賓語從句、主語從句(放在句首時)、表語從句常由whether引導.例如:
Whether she will go home or not is unknown.
她是否回家還不得而知.
Whether we shall raise ducks or geese remains to be decided.
我們是養鴨還是養鵝仍沒決定.
=It remains to be decided whether/if we shall raise ducks or geese.
[鞏固練習]
10. _______ we'll go camping tomorrow depends on the weather.
A. If B. Whether C. That D. Where
3)其它引導詞
連接代詞who, which, whom, whose有各自的意義,起連接作用,並在從句中充當語、賓語、表語、定語等;連接副詞when,where, why, how等有各自的意義,起連接作用,並在從句中充當狀語.
[鞏固練習]
11. -Do you remember _______ he came?
-Yes, I do. He came by car.
A. how B. when C. that D. if
12. It was a matter of _______ would take the position.
A. who B. whose C. whom D. whomever
13. -I drove to Zhuhai for the air show last week.
-Is that _______ you had a few days off?
A. why B. when C. what D. where
14. I read about it in some book or other, does it matter _______ it was?
A. where B. what C. how D. which
三、語氣
在It is necessary / natural / important / strange...+ that-clause這類句型里,that所引導的主語從句中謂語動詞用"should +原形",表虛似語氣.例如:
It is necessary that the problem should be settled at once.
這個問題必須馬上解決.
It's strange that he should have gone away without telling us.
他竟然沒向我們說一聲就走了,真是奇怪.
[鞏固練習]
15. It is necessary that a college student _______ at least a foreign language.
A. masters B. should master C. mastered D. will master
四、以it作形式主語的主語從句與強調句型的區別
"It be + adj./n. + that-clause"與強調句型均有It be...that...之類的語言標誌,但不同的是:前者中的that從句是主語從句.若刪掉其中的It be和that,則剩餘部分不論結構還是語意都不能成為一個句子;但若將後者中的It be和that去掉,則剩餘部分的結構和語意仍能構成一個完整的句子.強調句型譯為漢語時可加上"正是……"或"就是……"之類的字眼,而主語從句則不可以.
請比較下面兩個句子:
It is surprising that Mary should have won first place.
令人驚奇的是瑪莉竟然獲得了第一名.
It is Mary that has won first place.
正是瑪莉得了第一名.
第一句話中的It是形式主語,that引導的是主語從句.句中的It is和that無法刪除,一旦刪除句子就不成立.
第二句是強調句型,其中的It is和that可以去掉,因為沒有It is和that句子仍然很通順.
Key: 1-5 DBDBA 6-10 ACBDB 11-15 AAADB