介绍名词性从句以及怎样选择连接词

一、引导名词性从句的连接词
引导名词性从句的连接词可分为三类：
连接词：that,whether,if 不充当从句的任何成分）
连接代词：what, whatever, who, whoever, whom,
whose, which.
连接副词：when, where, how, why

不可省略的连词：
1. 介词后的连词
2. 引导主语从句和同位语从句的连词不可省略.
That she was chosen made us very happy.
We heard the news that our team had won.
比较：
whether与if 均为"是否"的意思. 但在下列情况下,whether 不能被if 取代：
1. whether引导主语从句并在句首
2. 引导表语从句
3. whether从句作介词宾语
4. 从句后有"or not"
Whether he will come is not clear.
大部分连接词引导的主语从句都可以置于句末,用 it充当形式主语.
It is not important who will go.
It is still unknown which team will win the match.
二. 主语从句
作句子主语的从句叫主语从句.主语从句通常由从属连词that,whether,if和连接代词what,who,which,whatever,whoever以及连接副词how,when,where,why等词引导.that在句中无词义,只起连接作用；连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用,在从句中充当从句的成分.例如：
What he wants to tell us is not clear. 他要跟我们说什么,还不清楚.
Who will win the match is still unknown. 谁能赢得这场比赛还不得而知.
It is known to us how he became a writer. 我们都知道他是如何成为一名作家的.
Where the English evening will be held has not yet been announced. 英语晚会将在哪里举行,还没有宣布.
有时为避免句子头重脚轻,常用形式主语it代替主语从句作形式主语放于句首,而把主语从句置于句末.主语从句后的谓语动词一般用单数形式.常用句型如下：
（1） It + be + 名词 + that从句
（2）It + be + 形容词 + that从句
（3）It + be + 动词的过去分词 + that从句
（4）It + 不及物动词 + that 从句
另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时,谓语动词要用虚拟语气“(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…
二、宾语从句
名词句用作宾语的从句叫宾语从句.引导宾语从句的关联词与引导主语从句表语从句的关联词大致一样,在句中可以作谓语动词或介词及非谓语动词的宾语.
1. 由连接词that引导的宾语从句
由连接词that引导宾语从句时,that在句中不担任任何成分,在口语或非正式的文体中常被省去,但如从句是并列句时,第二个分句前的that不可省.例如：
He has told me that he will go to Shanghai tomorrow. 他已经告诉我他明天要去上海.
We must never think (that) we are good in everything while others are good in nothing. 我们决不能认为自己什么都好,别人什么都不好.
注意：在demand、order、suggest、decide、insist, desire, demand, request, command等表示要求、命令、建议、决定等意义的动词后,宾语从句常用“（should）+ 动词原形”.例如：
I insist that she (should) do her work alone. 我坚持要她自己工作.
The commander ordered that troops (should) set off at once. 司令员命令部队马上出发.
2. 用who,whom, which, whose, what, when, where, why, how, whoever, whatever, whichever等关联词引导的宾语从句相当于特殊疑问句,应注意句子语序要用陈述语序.例如：
I want to know what he has told you. 我想知道他告诉了你什么.
She always thinks of how she can work well. 她总是在想怎样能把工作做好.
She will give whoever needs help a warm support. 凡需要帮助的人,她都会给予热情的支持.
3. 用whether或if引导的宾语从句,其主语和谓语的顺序也不能颠倒,仍保持陈述句语序.此外,whether与if 在作“是否”的意思讲时在下列情况下一般只能用whether,不用if：
a. 引导主语从句并在句首时；b. 引导表语从句时；c . 引导从句作介词宾语时；d. 从句后有“or not”时；e. 后接动词不定式时.例如：
Whether there is life on the moon is an interesting question. 月球上有没有生命是个有趣的问题.
The question is whether she should have a low opinion of the test?
Everything depends on whether we have enough money. 一切要看我们是否有足够的钱.
I wonder whether he will come or not. 我想知道他来还是不来.
Can you tell me whether to go or to stay? 你能否告诉我是去还是留?
4. 注意宾语从句中的时态呼应,当主句动词是现在时,从句根据自身的句子情况,而使用
不同时态.例如：
he studies English every day. （从句用一般现在时）
he studied English last term. （从句用一般过去时）
I know (that) he will study English next year. （从句用一般将来时）
he has studied English since 1998. （从句用现在完成时）
当主句动词是过去时态（could, would除外）,从句则要用相应的过去时态,如一般过去时,过去进行时,过去将来时等；当从句表示的是客观真理,科学原理,自然现象,则从句仍用现在时态.例如：
The teacher told us that Tom had left us for America．
5. think, believe, imagine, suppose等等动词引起的否定性宾语从句中,要把上述主句中的动词变为否定式.即将从句中的否定形式移到主句中.例如：
We don’t think you are here. 我们认为你不在这.
I don’t believe he will do so. 我相信他不会这样做.
三、表语从句
在句中作表语的从句叫表语从句.引导表语从句的关联词与引导主语从句的关联词大致一样,表语从句位于连系动词后,有时用as if引导.其基本结构为：主语 + 系动词 + that从句.例如：
The fact is that we have lost the game. 事实是我们已经输了这场比赛.
That’s just what I want. 这正是我想要的.
This is where our problem lies. 这就是我们的问题所在.
That is why he didn’t come to the meeting. 那就是他为什么不到会的原因.
It looks as if it is going to rain. 看上去天要下雨了.
需要注意的,当主语是reason时,表语从句要用that引导而不是because.例如：
The reason why he was late was that he missed the train by one minute this morning
四. 同位语从句
同位语从句说明其前面的名词的具体内容.同位语从句通常由that引导,可用于同位语从句的名词有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. 我们赢得这场比赛的消息令人激动.
I have no idea when he will come back home. 我不知道他什么时候回来.
The thought came to him that Mary had probably fallen ill. 他想到可能玛丽生病了.
同位语从句和定语从句的区别：
that作为关系代词,可以引导定语从句,充当句子成分,在从句中作宾语时可以省略； that引导同位语从句时,起连词的作用,没有实际意义,不充当句子成分,一般不能省略.
试比较下面两个例句:
I had no idea that you were here．（that引导同位语从句,不能省略）
Have you got the idea（that）this book gives you of life in ancient Greece?（that引导定语从句,作宾语,可以省略）
五、名词性that-从句
1）由从属连词that引导的从句叫做名词性that-从句. That只起连接主句和从句的作用,在从句中不担任任何成分,本身也没有词义.名词性that-从句在句中能充当主 语、宾语、表语、同位语和形容词宾语,例如：
主语：That he is still alive is sheer luck. 他还活着全靠运气.
宾语：John said that he was leaving for London on Wednesday. 约翰说他星期三要到伦敦去.
表语：The fact is that he has not been seen recently. 事实是近来谁也没有见过他.
同位语：The fact that he has not been seen recently disturbs everyone in his office.
近来谁也没有见过他,这一事实令办公室所有的人不安.
形容词宾语：I am glad that you are satisfied with your job.
你对工作满意我感到很高兴.
2）That-从句作主语通常用it作先行词,而将that-从句置于句末,例如：
It is quite clear that the whole project is doomed to failure. 很清楚,整个计划注定要失败.
It's a pity that you should have to leave. 你非走不可真是件憾事.

用it作形式主语的that-从句有以下四种不同的搭配关系：
a. It + be +形容词+ that-从句
It is necessary that… 有必要……
It is important that… 重要的是……
It is obvious that… 很明显……
b. It + be + -ed 分词+ that-从句
It is believed that… 人们相信……
It is known to all that… 从所周知……
It has been decided that… 已决定……
c. It + be +名词+ that-从句
It is common knowledge that… ……是常识
It is a surprise that… 令人惊奇的是……
It is a fact that… 事实是……
d. It +不及物动词+ that-分句
It appears that… 似乎……
It happens that… 碰巧……
It occurred to me that… 我突然想起……
六、名词性wh-从句

1）由wh-词引导的名词从句叫做名词性wh-从句.Wh-词包括who, whom,. whose, whoever, what, whatever, which, whichever等连接代词和where, when, how, why等连接副词.Wh-从句的语法功能除了和that-从句一样外,还可充当介词宾语、宾语补语和间接宾语等,例如：
主语： How the book will sell depends on its author. 书销售如何取决于作者本人.
直接宾语：In one's own home one can do what one likes. 在自己家里可以随心所欲.
间接宾语：The club will give whoever wins a prize.
俱乐部将给得胜者设奖.
表语： My question is who will take over president of the Foundation. 我的问题是谁将接任该基金会主席职位.
宾语补足语：She will name him whatever she wants to. 她高兴给他起什么名字就取什么名字.
同位语： I have no idea when he will return.
我不知道他什么时候回来.
形容词宾语：I'm not sure why she refused their invitation. 我尚不能肯定她为什么拒绝他们的邀请.
介词宾语： That depends on where we shall go.
那取决于我们去哪儿.
2）Wh-从句作主语也常用先行词it做形式主语,而将wh-从句置于句末,例如：
It is not yet decided who will do that job.
还没决定谁做这项工作.
It remains unknown when they are going to get married. 他们何时结婚依然不明.
七、if, whether引导的名词从句
1）yes-no型疑问从句
从属连词if, whether引导的名词从句是由一般疑问句或选择疑问转化而来的,因此也分别被称为yes-no型疑问句从句和选择型疑问从句,其功能和wh-从句的功能相同, 例如：
主语：Whether the plan is feasible remains to be proved. 这一计划是否可行还有等证实.
宾语：Let us know whether / if you can finish the article before Friday. 请让我们知道你是否能在星期五以前把文章写完.
表语：The point is whether we should lend him the money. 问题在于我们是否应该借钱给他.
同位语：They are investigating the question whether the man is trustworthy. 他们调查他是否值得信赖.
形容词宾语： She's doubtful whether we shall be able to come. 她怀疑我们是否能够前来.
介词宾语： I worry about whether he can pass through the crisis of his illness. 我担心他是否能度过疾病的危险期.
2）选择性疑问从句
选择性疑问从句由关联词if/whether…or或whethe…or not构成,例如：
Please tell me whether / if they are Swedish or Danish. 请告诉我他们是瑞典人还是丹麦人.
I don't care whether you like the plan or not.我不在乎你是否喜欢该计划.
八、否定转移
1) 将think, believe, suppose, expect, fancy, imagine等动词后面宾语从句的否定词转移到主句中,即主句的谓语动词用否定式,而从句的谓语动词用肯定式.
I don't think I know you. 我想我并不认识你.
I don' t believe he will come. 我相信他不回来.
注意：若谓语动词为hope,宾语从句中的否定词不能转移.
I hope you weren't ill. 我想你没有生病吧.
2) 将seem, appear 等后的从句的否定转移到前面.
It doesn't seem that they know where to go.
看来他们不知道往哪去.
It doesn't appear that we'll have a sunny day tomorrow.
看来我们明天不会碰上好天气.
3) 有时将动名词,介词短语或整个从句的否定转变为对谓语动词的否定.
I don't remember having ever seen such a man.
我记得从未见过这样一个人. (not否定动名词短语 having…)
It's not a place where anyone would expect to see strange characters on the street.
在这里,人们不会想到在街上会碰上陌生的人.
(anyone 作主语,从句中的谓语动词不能用否定形式.)
4) 有时状语或状语从句中否定可以转移到谓语动词前.
The ant is not gathering this for itself alone. (否定状语) 蚂蚁不只是为自己采食.
He was not ready to believe something just because Aristotle said so. (否定because状语) 他并不因亚里斯多德说过如何如何,就轻信此事.
She had not been married many weeks when that man's younger brother saw her and was struck by her beauty. (否定状语many weeks) 她结婚还不到几个月,这个人的弟弟就看见她了,并对她的美貌着了迷.
九、高考热点透视
1. ___ is a fact that English is being accepted as an international language. (NMET 1995)
A. There B. This C. That D. It
答案D.当名词从句在句中作主语时,为避免句子头重脚轻,常用it作形式主语置于句首,而将真正的主语从句放在句尾.此时it只起先行引导作用,本身无实义.此句也可以改写为：That English is being accepted as an international language is a fact.
2．A computer can only do ____ you have instructed it to do．（NMET2001）
A．how B．after C．what D．when
答案C.从句子结构可知,句子的空白处应该填引导宾语从句的连词,做主句谓语动词do的宾语,同时该连接词还是从句中的do的宾语,因此,此处的连接词应该用what.
3. He asked ____ for a violin．（MET1992）
A. did I pay how much B. I paid how much
C. how much did I pay D. how much I paid
答案：D.宾语从句相当于特殊疑问句,句子语序要用陈述语序.
4. What the doctors really doubt is my mother will recover from the serious disease soon．（上海2001年春季招生）
A. when B. how C. whether D. why
答案C.这是一个表语从句.根据 doubt一词可知,所怀疑的应是是否能治好病,所以要填whether.这句话的意思是“医生真的怀疑我妈妈是否能很快从重病中恢复过来.”
5．It is generally considered unwise to give a child _____he or she wants. (NMET1997)
A. however B. whatever C. whichever D. whenever
答案B.根据句意“一般认为孩子要什么就给什么是不好的.”可以看出后面的从句应是一个宾语从句,而从句中wants缺少宾语,A. however 和D. whenever是不能作宾语的；排除A和D,whichever表示“无论哪一个,无论哪些”,应表示一定范围内的人或物,此处没有涉及事物的范围,所以应选 B．whatever,表示“无论什么”.
6. ______leaves the room last ought to turn off the lights. (MET1988)
A. Anyone B. The person C. Whoever D. Who
答案C.本题句子的意思是：无论谁最后离开房间一定要把灯关掉.本题考查连接代词whoever引导的名词性从句,连接代词whoever可以引导名词性从句,并在从句中作主语,相当于any person who或The person who, 意为“一切……的人”.而anyone和the person均非连词,不能引导从句,况who leaves the room last意为“某个最后离开房间的人”,与题意不符,如果要选A. Anyone或B. The person,都必须在它们后面再加上引导定语从句的关系代词who.如果要选D. Who就体现不出“无论谁”的含义了.
7. Sarah hopes to become a friend of ______shares her interests. (Shanghai1995)
A. anyone B. whomever C. whoever D. no matter who
答案为C.本题句子的意思是：Sarah希望跟自己有共同爱好的人交朋友.疑问词+ever引导的名词性从句与no matter+疑问词引导的从句的区别是：前者既可以引导名词性从句也可以引导让步状语从句；后者只能引导让步状语从句.首先排除A和D,从句中需要的是主语,所以whomever也不行.
8. ---- I drove to Zhuhai for the air show last week.
---- Is that ______ you had a few days off ? ( NMET1999)
A. why B. what C. when D. where
答案A.根据语境,甲说上周驱车去珠海观看航模展览.乙据此来询问甲这是否是请几天假的原因,故答案是A.答案B,C, D均与该题语境不符.根据上句提供的语境,下句应该问“那就是你为什么离开几天的原因吗?”
9. I still remember ______ this used to be a quiet village. ( NMET1993)
A. when B. how C. where D. what
答案A.根据从句中缺少的句子成分是状语,排除D．what,而答案C, D均与题意不符,所以应选A．when.used to be表示一种过去存在的状态,本句的意思是“我仍然记得这里在什么时候是个宁静的地方.”
10．I read about it in some book or other,does it matter ____ it was?（2001春季招生）
A．where B．what C．how D．which
答案D.这是一个主语从句.主语从句中缺少表语.从上句的意思分析,应是哪本书,所以要填which,这句话的意思是“我在某本书中读到过有关这方面的内容,是哪一本书重要吗?”.
11. Information has been put forward ____ more middle school graduates will be admitted into universities.
A. while B. that C when D. as (2001年上海)
答案B.该题考查that引导的同位语从句.同位语从句通常由that引导,接在fact, news, promise, possibility, information, doubt, message名词后,用来解释或说明名词的内容.
12. —I think it is going to be a big problem.
—Yes, it could be.
—I wonder ______ we can do about it. (北京 2002春季)
A、if B、how C、what D、that
答案C.本题考察名词性从句的连接词的用法.wonder后面应跟宾语从句,而从句中的谓语动词do是及物动词,可见从句缺少一个代替宾语的成分,我们可以用排除法排除不作成分的if和that,再排除引导方式状语的how,答案是C,句子的意思是“我们能就此做些什么”.
十、专项考点练习
1. ________that they found an unusual plant in the forest.
A. It is said B. They are said C. It said D. It says
2. _____ caused the accident is still a complete mystery.
A. What B. That C. How D. Where
3. It worried Mary a lot _____ she would pass the college entrance examination.
A. whether B. if C. that D. how
4. Shanghai has taken on a new look. It isn’t like _____ it used to be .
A .what B. how C. that D. which
5. ____ is no possibility ______ Bob will win the first prize in the match.
A. There, that B. It, that C. There, whether D. It, whether
6. Little Tommy was reluctant to tell the schoolmaster ____ he had done the day before.
A .that B. how C .what D. where
7. The old man smiled when he saw how pretty _____ up to be during the past few years.
A. had his daughter grown B. would his daughter grow
C. his daughter would grow D. his daughter had grown
8. Have you seen Mary lately? My boss wants to know _______.
A. how she is getting along B. how is she getting along
C. what she is getting along D. what is she getting along
9. ____surprised me most was _____such a little girl of seven could play the violin so well.
A. That; what B. What; that C. That; that D. What; what
10. These wild flowers are so special I would do ______ I can to save them.
A. whatever B. which C. that D. whichever
11. _____ helped to save the drowning girl is worth praising.
A. Who B. Anyone C. Whoever D. The person
12. Eat _____ you like and leave the others for _____ comes in late.
A. any; who B. every; whoever C. whichever; whoever D. either; whoever
13. ____ she couldn’t understand was _____ fewer and fewer students showed interest in her lessons.
A. What; why B. That; why C. What; because D. Why; that
14. It was ____ he said ___ disappointed me.
A. What; that B. That; that C. What; what D. That;what
15. It was ordered that all the soldiers _______to the front.
A. should send B. must be sent C. should be sent D. must go
16. The true value of life is not in ______, but _______.
A. which we get; what give we B. what we get; what we give
C. which do we get; what do we give D. how we get; that we give
17. We are all for your proposal that the discussion _______.
A. be put off B. was put off C. should put off D. is to be put off
18. Go and get your coat．It's ____ you left it．
A. where B. there C. here where D. where there
19. Sarah hopes to become a friend of ______ shares her interests.
A. anyone B. whomever C. whoever D. no matter who
20. You can’t imagine ______ when they received these nice Christmas presents.
A. how they were excited B. how excited they were
C. how excited were they D. they were how excited
Keys:
1---5 A A ABA 6---10 CDABA 11----15 CCAA C 16---20 BAACB

其实很简单,你只要记着名词性从句只有that在引导的句子里不做任何成分,而what这类词是在句子里做主语,宾语的成分.还有:表语从句是关系词前有is之类的系动词,宾语从句是跟在动词之后的句子,状语从句就是分的好多种情况了,不用专门去记它.连接词,连接副词,连接代词这些记了就更乱了,...

不是写的多就一定好,我只说一句话:(精辟好记)
语法书上讲的重点:"名词性从句疑问词,缺什么,选什么,什么都不缺用that"
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Happy new year!^_^