名词性从句知识点复习
名词性从句相关知识点复习
一、主语从句:英语中用作主语的从句就叫主语从句。
(一)主语从句的引导词:
连词:that、whether、if
连接代词:who、whom、whose、what、which
连接副词:when、where、why、how
复合词:whoever、whomever、whatever、whichever
1.whether、if引导主语从句的区别:
(1)主语从句置于句首时只用whether.
Whether he will come here is not decided yet.
(2)当用it作形式主语,主语从句置于句中时,whether/if都可以。
It is unknown whether/if she will come today.
2.what 引导的主语从句一般放在句首,谓语动词的单复数取决于主句中作表语的名词。 What we need is more time.
What they need are more English books.
3.连接副词when、where、why、how引导主语从句,既可以出现在句首,也可以用it作形式主语。
Why Tom was late is still unknown.
It is quite clear why he did it.
4.连词that的用法:
(1)that在句中无词义,只起连接作用,放在句首时,不能省略。
That he will come to the meeting is certain.
(2)为避免句子头重脚轻,常用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,常用句式:
1.It be+n+that从句
It is a pity that he can't come to my birthday party.
2.It be + adj + that从句
It is quite clear that the whole project will fail.
3. It be + 及物动词过去分词 +that从句
It is ordered that we (should) get everything ready this evening.
4. It + 不及物动词 + that从句
It happened that I didn't take any money with me.
5.单个的主语从句表示单一概念时,谓语要用单数形式。
What he wants to tell us is not clear.
6.主语为两个并列的主语从句时,谓语用复数形式。
When they will start and where they will go have not been decided yet.
7.两个并列连词连接一个主语从句时,谓语用单数形式。
When and where the meeting will begin has not been decided.
二、同位语从句:英语中用作同位语的从句就叫同位语从句,位于一名词之后,用以解释说明该名词的具体内容。
(一、)常见的同位语从句一般由that引导:
可由that引导同位语从句的名词有:advice, decision, fact, hope, idea, information, news, promise, proposal, report, suggestion, word, problem, question, doubt, thought等。
(二、)引导同位语从句的that在从句中不充当句子成分,无词意,但不可省略。
(三、)虚拟语气在同位语从句中的运用
若被同位语从句前的名词是表示要求,命令,建议等意义的词汇时,同位语从句的谓语动词要用“(should)+V”。
(四、)学习同位语从句需要注意的问题:
1.表达“是否”概念时,要用whether而不能用if.
I have no idea whether you are interested in working for her.
2.名词doubt后的同位语从句用whether引导,no doubt后的同位语从句用that引导。 We have some doubt whether they can complete the task in time.
There is no doubt that he will keep his promise.
(五、)同位语从句与定语从句的区别
1.引导同位语从句的that是连词,只起连接作用,在从句中不作句子成分,而引导定语从句的that是关系代词,除起连接作用外,还要在从句中充当句子成分。
2.同位语从句中连词that一般不省略,而限定性定语从句中that在从句中作宾语时,可以省略。
三、宾语从句:英语中用作宾语的从句就叫宾语从句。
(一)、宾语从句的引导词:
连词:that、whether、if
连接代词:who、whom、 whose、which、what
连接副词:when、where、 why、how
复合词:whenever、 wherever、whoever……
(二)、引导词的运用:
1. that引导宾语从句时,无语法功能和词汇意义,可省略。(注意:若从句是并列句时,第一个that可以省略,但第二个及后面分句中的that引导词不可省略)
She said (that) she would come here and that I should wait for her till Monday.
2.表“是否”时只用whether不用if的三种情况:
(1)与or not连用时
We don’t know whether Tom will attend the meeting or not.
(2)介词之后
Everything depends on whether you like it.
(3)后接不定式时
I can’t decide whether to stay.
(三)连接代词的作用:
引导宾语从句时,在从句中起代词的作用,可以作从句的主语,宾语,表语,定语
(四)宾语从句中需注意的三个问题:
1.否定前移:即当主句主语是I/we,时态为一般现在时,动词think、consider、believe、suppose、imagine、expect、guess等后面的宾语从句中的否定词经常前移至主句。
I don’t believe he has finished his work, has he?
2. It作形式宾语:
带有复合宾语的句子,that引导的宾语从句常被移到句子后而用It作形式宾语。 We think it impossible that you can finish the job today.
3.“doubt+宾语从句”句型中连词的选用
肯定句中用whether/if,否定句和疑问句中用that.
四、表语从句
(一)、可接表语从句的系动词有:
be、look、remain、stay、seem、feel、smell等
(二)表语从句的引导词:
连词:that、whether、because、as if(if 不可以引导表语从句)
(三)表语从句引导词的运用:
that引导表语从句时,无词义,也不充当句子成分,但不可省略。
The fact is that we are behind other groups.
(四)表语从句中引导词必须用that的情况:
1.主语是the result时:
The result is that many of them become fat finally.
2.主语是the reason时:
The reason was that he was too busy.
3.由why引导的从句作主语时:
Why they put off the match is that the weather was too bad.
4. 在句型“the truth/fact is that„„”
The truth is that I didn’t know about it at all.
5.连词because引导表语从句通常只用于“this/that/it is/was because……”结构中。且句子主语不能是reason或cause等表示原因的词。
6.as if/ though 引导表语从句时常置于系动词look、seem、sound、be、become等后面。 The elephant feels as if he were a wall.
7.why也可引导表语从句,常用于句型:“This/That is why......”。
8.当主句的主语是reason时,表语从句用that引导,不能用why或because,这种用法常见于句型:“The reason why...is that...”如:
The reason why he came late was that he got up late.
易混补充:that与what引导名词性从句的区别
1.What引导名词性从句在从句中作主语、宾语、表语;而that引导名词性从句时不作任何成分且无任何词义。
2.what, who 等与whatever, whoever的区别
前者指具体的物或人,后者指任何一个人或物。对比:
I don’t know who can share my joys and sorrows.
I will make friends with whoever can share my joys and sorrows.
附练习几个:
1.Before a problem can be solved, it must be obvious_______the problem itself is.
2.There is clear evidence ________the most difficult feeling of all to interpret is bodily pain.
3.To prove the quality of our products, we asked fof suggestions_________had used the products.
4.________struck me most in the movie was the father’s deep love for his son.
5.Our teachers always tells us to believe in _________we do and who we are if we want to succeed.
6.When the news came_________the war broke out, he decided to serve in the army.
7.It’s by no means clear ________the president can do to end the strike.
8.It surprised us all __________so many passengers were killed in the accident.
9._______is widely acknowledged that_________there is life, there is hope.
10.The headteacher said _______________broke the rules would be punished.
11.Police have found __________appears to be the lost ancient statue.
12._______ you have done might do harm to other people.
13. I have no idea at all ______ they talked about in the next door room.
14. _______ leaves the room last ought to turn off the lights.
15. Anyone _____ leaves the room last ought to turn off the lights.
16. These photographs will show you ______ our village looks like.
17. Can you make sure _______ Alice has put the gold ring?
18. No one can be sure _______ man will look like in a million years.
19. It worried Tracy a bit _______ her hair was turning grey.
20. _______ you don’t like the singer is none of my business.
21. ________ Bob said at the meeting astonished everybody present.
22. My friends asked ______ I paid for the violin.
23. As his best friend, I can make accurate guesses about ______ he will do or think.
24. _______ is a fact that English is accepted as an international language.
25. Sarah hopes to become a friend of _______ shares her interests.
26. _______ we can’t get seems better than ________ we have.
27. _______ we’ll go camping tomorrow depends on the weather.
28. It is generally considered unwise to give a child ________ he or she wants.
29. ________ caused the accident is still a complete mystery.
30. It was a matter of ________ would take the position.
31. It has been proved ________ eating vegetables helps to protect you against serious illnesses.
32. _______ has helped to save the drowning girl is worth praising.
33. These wild flowers are so special _______ I would do _______ I can to save them.
34. The reason ______ I have to go is ______ my mother is ill in bed.
35. What the doctors really doubt is ____ my mother will recover from the serious disease soon.
36. _______ is no possibility _______ Bob can win the first prize in the speaking competition.
37. _______ matters most in learning English is enough practice.
38. ______ we are sure about is the need to prevent children from being spoiled.
39. ______ is known to us all is that the 2008 Olympic Games took place in Beijing.
40. We’re trying to figure out _______ quite a number of birds are dying out.
41. Tomorrow is Tom’s birthday. Have you got any idea _______ the party is to be held?
42. A modern city has been set up in ______ was a wasteland ten years ago.
43. Parents are taught to understand ______ important education is to their children’s future.
44. The road is covered with snow. I can't understand ______ they insist on going by motor-bike.
45. It hasn’t been decided _______ Betty will come. It all depends.
46. The question is _______ the film is worth seeing.