高中名词性从句知识点汇总.doc

名词性从句

名词性从句知识点汇总

在句中起名词作用从句叫做名词性从句。名词性从句的功能相当于名词短语，在复合句中能担当主语、宾语、表语、同位语等。根据它在句中不同的语法功能，名词性从句分为主语从句、宾语从句、表语从句和同位语从句。名词性从句的引导词可分为3类：
从属连词：只起连接作用，不充当从句中的任何成分。包括：that,whether,if,as if,as though
连接代词：既起连接作用，本身又作从句的主语、宾语、表语或定语。包括：
who,whom,whose,which,what,whoever,whatever,whichever,whomever.
连接副词：既起连接作用，本身又作从句的状语。包括:when, where,how,why
s
一、 主语从句
可以直接放在句首，也可以用形式主语it代替，将主语从句放在句末。
1. that引导的主语从句
that引导主语从句时只起连接作用，没有实际意义，也不在从句中作任何成分，但不能省略。
That the earth moves around the sun is known to all.
2. whether,if引导主语从句
whether：引导主语从句既可以放在句首，也可以放在句末，只起连接作用，不作成分
if：引导主语从句只能放在句末，前面用it作形式主语。
whether you can succeed or not depends on how hard you work at it.
It is unknown whether/if he has agreed to my plan.
3. 连接代词或连接副词引导主语从句
连接代词在从句中作主语、宾语、表语或定语。
连接副词在从句中作状语。
What they need are a car and some water.
Why they suddenly disappointed still remains a mystery.
4. it 作形式主语的主语从句
1) It+be+adj./n./过去分词+that 从句
It has been predicted that mobile phones might soon replace our wallets.
2) It+seem(ed)/happen(ed)等不及物动词及短语+that 从句
It seemed that each of them was satisfied with the results.
3) It doesn’t matter+how/whether
It doesn’t matter whether he will join the club or not.
4) that引导主语从句出现在疑问句中，用it作形式主语，把主语从句后置
Is it likely that your friend will come this evening?
5) 当主语从句出现在感叹句中时，要以it作形式主语，而把主语从句后置
What a pity it is that you missed a wonderful football match!

二、 宾语从句
1. 动词接宾语从句
1) 宾语从句紧跟在及物动词后：She wondered who had sent the flowers.
2) 常用it作形式宾语：He had made it clear that the meeting not be postponed.(有宾补的情况下)
2. 介词接宾语从句
1) 介词后面可以跟whether和wh-类连接词引导的宾语从句
He only cares about whether the eyewitness has given true information.
2) 介词except,but,besides,in后有时可以直接接that引导的宾语从句。除这些之外，that引导的从句一般不直接作介词的宾语。其他介词后接that从句作宾语时，必须用it作形式宾语。
I didn’t tell him anything except that I needed the money.
You may depend on it that I should always help you.
3. 系表结构接宾语从句
Sure,certain,glad,pleased,happy,afraid,surprised,satisfied,sorry等表示情感的形容词与be一起构成系表结构，其后的从句也可视为宾语从句。
I’m confident that you will get the job.
I’m glad that you can come here on time.
4. 只用whether不用if的情况
1) 在介词后引导宾语从句：Everything depend on whether you agree with us.
2) 宾语从句置于句首:Whether they like the presents, we don’t know.
3) 与or not连用时：I want to know whether or not the train goes to King street.
4) 与不定式连用时: I can’t decided whether to stay.
5) 在动词discuss, wonder, doubt, leave, put后引导宾语从句:
We discussed whether we should close the shop.
5. 宾语从句中不能省略that的情况
1) 宾语从句前有插入语：We hope,on the contrary,that he will stay at home with us.
2) 宾语从句紧跟在间接宾语之后时，或主语状语置于宾语从句之前时
He told me that he was leaving for Australia.
I realized at once that I hadn’t turn off the gas.
3) 当it作形式宾语，后接that引导的宾语从句时
I don’t think it polite that they left without saying thanks to us.
4) that引导的从句位于句首
That our team will win,I believe.
5) 宾语从句在except,but,besides,in等介词之后
He also likes playing the piano besides that he is good at playing basketball.
6) that引导的从句与其他引导词引导的从句作并列宾语
I know where we will go and that we’ll be back in three days.
7) 多个并列的that引导的宾语从句，只有第一个that可以省略
8) 宾语从句的主语是非谓语动词或从句
The doctor said that taking exercise was the best way of losing weight.
9) 宾语从句的主语是this,that或有this,that修饰时
She told me that that was why she was late.
10) 宾语从句为主从复合句，从句位于宾语从句的前部
I promised that if anyone came to set me free,I would make him king over the earth.

三、 表语从句
表语从句位于主句的连系动词be,seem,look,sound,taste,feel,remain,appear等之后。
1. that,whether引导的表语从句
只起连接作用，不作成分，that无词义，不能省略。Whether意为是否，不能换成if。
One problem is that I don’t look any different from other people.
2.as if,as though, because
1)as if,as though引导的表语从句，可用陈述语气，也可用虚拟语气。常跟在特定动词后面，如seem,appear,look,taste,sound,feel等。
You look as if you’ve had a good time.
He looks as if he were from the Mars.
2) because引导表语从句时，主句的主语不能用reason。如果主句的主语是reason表语从句用that，不能用why或because。常见句型为The reason(why)...is that...
3) wh-类连接词引导的表语从句，通常不含有意义，而是分别表示具体地点、时间、原因和方式等。
This is why I think my happiest days will be in the future.
4) 表语从句用虚拟语气的情况：主句的主语是advice, demand, order, suggestion, requirement, request, command等时，表语从句用虚拟语气，结构是(should)+动词原形。
His suggestion is that we (should) set off at once.

四、 同位语从句
往往用来说明某些名词的实际内容或对该名词作进一步解释。这类名词常见的有：fact,news,idea,truth,hope,problem,information,wish,suggestion,conclusion等。
1. that引导同位语从句：通常从句意义完整，that无词义，只起连接作用，不可省略。
I’ve got a feeling that one day he’ll be famous.
2. whether, when, where, why, how等引导同位语从句。whether意为是否，在句子中不作成分，其他的连接词具有实义，并在句中作成分。If 不能引导同位语从句。
The student asked me the question whether the book was worth reading.
I have no idea when we will have a long holiday.
3. 被分隔的同位语从句：主句的谓语比较短时，同位语从句常被分隔，形成：主语+谓语+同位语从句
The notice came around two in the afternoon that the meeting would be postponed.
4. 同位语从句中的虚拟语气：当主语是advice,proposal,suggestion等时，要用虚拟语气，(should)+动词原形。
The suggestion came from the chairman that the rule (should) be adopted.
5. 同位语从句和定语从句的区别
1) 修饰词：同位语从句前被修饰词只能是idea, fact, news, hope等有一定内涵的名词。
定语从句前被修饰词可以是名词、代词、主句的一部分或整个主句。
2) 性质：同位语从句相当于一个名词，对前面的抽象名词进行说明和解释
定语从句相当于一个形容词，对先行词进行修饰或限制。
3) 连接词：有些连接词how,whether,what可引导同位语从句，不能引导定语从句；而which能引导定语从句，却不能单独使用引导同位语从句。例如：
The question whether we need it has not been considered.
This is a simple idea,but one which is hard to put into practice.
4) 成分：that在同位语从句中仅起连接作用，不充当任何成分，不能省略，也不能用which来代替。
that引导定语从句，在从句中一般作主语或宾语，指物时可以用which来代替，作宾语常被省略。
But they forget the fact that Canada is 5,500 km from coast to coast.
The news that he told us just now is unbelievable.

五、 连接词what与that 的区别
1. 引导名词性从句时，what在从句中要充当句子成分，意为“……的事物/地方/人”；that不作任何成分，只起连接作用，没有实际意义。
What the post says is interesting.
I heard that he joined the army.
2. 当名词性从句已有疑问词引导时，不可再加that
I don’t understand what you said just now.

六、 wh-ever与no matter wh-的区别
wh-既可以引导名词性从句，又可以引导让步状语从句；而no matter wh-只能引导让步状语从句。
He wouldn’t believe whatever I said. Whatever I said,he wouldn’t believe me.
七、 连接词whether和if的区别
1. 在引导主语从句、表语从句、同位语从句时，一般用whether不用if。
2. 在主语从句中用it作形式主语时，whether和if都可以用，但在句首时只能用whether。
Whether they will have a picnic tomorrow isn’t know.
It isn’t certain whether/if you’ll attend the meeting.
八、 doubt,be sure
I doubt whether/if... doubt用于肯定句，用whether/if
There’s no doubt that.. doubt用于否定句，用that
I’m sure that... sure用于肯定句，用that
I’m not sure whether/if... sure用于否定句，用whether/if

课堂练习
一、在下列句子空白处填入适当的单词：
1. Grandma pointed to the hospital and said,”That’s__________I was born.
2. Is it true that Mike refused an offer from Yale University yesterday?
Yeah,but I have no idea____________he did it;that’s one of his favorite university.
3. ____________the delayed flight will take off depends much on the weather.
4. From space,the earth looks blue.This is_________about seventy-one percent of its surface is covered by water.
5. Do not let any failure discourage you,for you can never tell______close you may be to victory.
6. I made a promise to myself______this year,my first year in high school,would be different.
7. Scientists study__________human brains work to make computers.
8. I’m afraid he’s more of a talker than a doer,which is______he never finishes anything.
9. ________worries me a lot is that I keep forgetting what I have just done.
10. I really don’t know________it was that I put my wallet.
二、单句改错
1. So if they said was true,I would have a chance of winning the prize.
2. Word came that free souvenirs would be given to anyone whoever come first.
3. The reason why he was late is because he wasn’t informed of the change of time.
4. The news our team won the match was encouraging.
5. I can never understand how Mary said nothing about her wrongs.
6. I have been admitted to Beijing University excited me.
7. It depends on if we have enough money.
8. He is a good student except he is a bit care less sometimes.
9. He said he was satisfied with his stay here and he would come back again.
10. If it is true remains a question.
三、单选题
1. The best moment for the football star was______he scored the winning goal.
A. where Bwhen C.how D.why
2. Pick yourself up.Courage is doing_____you’re afraid to do.
A. that B.what C.how D.whether
3. Some people believe______has happened before or is happening now will repeat itself in the future.
A. whatever B.whenever C.wherever D.however
4. Exactly_______the potato was introduced into Europe is uncertain,but it was probably around 1565.
A. whether B.why C.when D.how
5. What a mess!You are always so lazy! - I’m not to blame,mum. I am________you have made me.
A.how B.what C.that D.who
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