名詞性從句考點(diǎn)精析

胡菊英 胡俊

名詞性從句，是指在復(fù)合句中性質(zhì)相當(dāng)于名詞的從句。它包括主語從句、賓語從句、表語從句和同位語從句。歷年全國(guó)各省市高考試題對(duì)名詞性從句都考查較多。

例1 （2013·重慶卷）That struck me most in the movie was the fathers deep love for his son.

解析 That→What。此題考查主語從句，what在從句中充當(dāng)主語。

例2 （2015·全國(guó)卷Ⅱ）After looking at the toy for some time， he turned around and found where his parents were missing.

解析 where→that，或去掉where。此題考查賓語從句，that在句中不充當(dāng)任何成分，可以省略。

例3 （2014·北京卷） The best moment for the football star was _____ he scored the winning goal.

解析 when。考查表語從句。句意：對(duì)一個(gè)足球明星來說，進(jìn)球得分的時(shí)刻是最好的時(shí)刻。根據(jù)題干中的moment一詞推斷，后面說的應(yīng)該是“……的時(shí)候”。

例4 （2012·浙江卷） I made a promise to myself _______ this year， my first year in high school， would be different.

解析 that。此題考查同位語從句。句意：我對(duì)自己作出了承諾，今年——我讀中學(xué)的第一年——將會(huì)有所不同。that引導(dǎo)的從句是對(duì)promise進(jìn)行解釋和說明，that在句中不充當(dāng)任何成分，通常不能省略。

縱觀歷年高考試題，我們可以發(fā)現(xiàn)名詞性從句考查的焦點(diǎn)主要在以下幾個(gè)方面：

[that與what的區(qū)別]

1. 連詞that在引導(dǎo)名詞性從句時(shí)本身沒有意義，在從句中不充當(dāng)任何句子成分。

that引導(dǎo)主語從句位于句首時(shí)，that無意義，但是不可省略。如：That you didnt know the rules wont be an excuse for your failure.

that引導(dǎo)表語從句時(shí)，一般不省略。如：My decision is that all of us are to start at 6 oclock tomorrow morning.

that引導(dǎo)同位語從句時(shí)，應(yīng)在某些抽象名詞如fact， hope， desire， thought， suggestion， idea， news， problem， possibility等后，對(duì)前面的名詞起補(bǔ)充說明的作用，在從句中不充當(dāng)任何成分，一般不省略。如：Modern science has given clear evidence that smoking can lead to many diseases.

that引導(dǎo)賓語從句時(shí)，在句中不充當(dāng)任何成分，在口語或非正式的文體中常被省去，但如果從句是并列句，第二個(gè)分句前的that不可省略。如：He said （that） he liked rain very much and that he wouldnt use an umbrella when it was raining.

2. 連詞what引導(dǎo)名詞性從句時(shí)，what在從句中充當(dāng)主語、賓語、表語等。如：

What matters most in learning English is enough practice. （主語）

What he considered a great proposal was turned down by the boss. （賓語）

China is no longer what she used to be. （表語）

[名詞性從句的語序、時(shí)態(tài)問題]

由who， whom， which， whose， what， when， where， why， how， whoever， whichever等關(guān)聯(lián)詞引導(dǎo)的名詞性從句，應(yīng)注意句子要用陳述語序。如：

Scientists study how human brains work to make computers.

I want to know what he has told you.

She always thinks of how she can work well.

在含有賓語從句的主從復(fù)合句中，當(dāng)主句的謂語動(dòng)詞是過去時(shí)態(tài)時(shí)，從句須用表示過去的某種時(shí)態(tài)；當(dāng)賓語從句表述的是客觀事實(shí)、科學(xué)真理以及格言等時(shí)，其時(shí)態(tài)不受主句限制，常用一般現(xiàn)在時(shí)；當(dāng)主句的時(shí)態(tài)是一般現(xiàn)在時(shí)、現(xiàn)在進(jìn)行時(shí)、現(xiàn)在完成時(shí)等，從句可根據(jù)情況選用各種適合的時(shí)態(tài)。如：

He asked when they would go to the party.

The teacher told us that light travels faster than sound.

Do you know he has gone to Beijing？

[it作形式主語/賓語的用法]

1. that引導(dǎo)主語從句時(shí)，常用it作形式主語，常見的句型有：

it+be+形容詞（obvious， natural， surprising， good， wonderful， possible， etc.）+that從句。如：It is obvious that they should get well prepared for their future.

it+be+名詞詞組（no wonder， an honor， a good thing， a pity）+that從句。如：He plays computers all day. It is no wonder that he failed to pass the test.

it+be+過去分詞（said， reported， thought， expected， announced， etc.）+that從句。如：It is decided that the meeting has been put off till next Monday.

2. 特殊疑問詞引導(dǎo)主語從句，常用it作形式主語。如：It makes no difference where we shall have the meeting.

3. 在可以接復(fù)合賓語的動(dòng)詞之后，如think， make， consider等，可以用it作形式賓語。如：He has made it clear that he will not give in.

[whether與if的區(qū)別]

whether和if在賓語從句中經(jīng)常可以互換，但下列情況常用whether，不用if。

1. 與or或or not連用時(shí)只能用whether。如：He must answer the question whether he agrees to it or not.

2. 從句作介詞賓語時(shí)只能用whether。如：It depends on whether you can do the work well.

3. 在引導(dǎo)主語從句、表語從句和同位語從句時(shí)一般用whether不用if。如：

It doesnt matter whether you pay by cash or credit card in this store.

The question is whether it is worth trying.

[“疑問詞+ever”引導(dǎo)的名詞性從句]

1. “疑問詞+ever”可引導(dǎo)名詞性從句，在主從句中要充當(dāng)一定的成分。whoever與whatever表示泛指，意為“無論誰”“無論什么”；whichever表示在特定范圍內(nèi)選擇，意為“無論……的哪一個(gè)/哪一些”。如：

There are various things on sale， so you can choose whatever interests you.

We have plenty of books. You may take whichever you like.

2. “疑問詞+ever”還可以引導(dǎo)讓步狀語從句。

3. “no matter+疑問詞”只能引導(dǎo)讓步狀語從句。

[名詞性從句中的虛擬語氣]

1. 表示“建議、要求、請(qǐng)求或命令”等意義的詞出現(xiàn)在主語、表語和同位語從句中時(shí)，謂語要用“should+動(dòng)詞原形”的虛擬結(jié)構(gòu)，should可以省略。如：

Its suggested that one （should） take exercise every day. （主語從句）

His suggestion is that you （should） take measures at once. （表語從句）

He made a suggestion that you （should） take measures at once. （同位語從句）

2. 在主語從句中，表示“做某事很重要、很必要、很遺憾或者很奇怪”時(shí)，謂語也要用“should +動(dòng)詞原形”，should可以省略。如：

Its important/necessary that we （should） learn English well.

Its a pity that he （should） be late again.

[考查同位語從句與定語從句的區(qū)別]

同位語從句是對(duì)前面名詞的內(nèi)容作進(jìn)一步的解釋、說明，引導(dǎo)詞that只起引導(dǎo)作用，在句中不作任何成分，一般不可省略；定語從句是對(duì)前面名詞進(jìn)行修飾、限制，引導(dǎo)詞在句中作一定的句子成分，作賓語時(shí)可以省略。如：

The news that they had won the game soon spread over the whole school.

他們贏得比賽的消息很快就傳遍了整個(gè)學(xué)校。（同位語從句，進(jìn)一步解釋the news的內(nèi)容）

The news （that） you told me yesterday was really disappointing.

你昨天告訴我的消息真的很令人失望。（定語從句，它指的是“你昨天告訴我的那個(gè)消息”）