Question

英语语法中的各种从句定义与应用、例句等，分别说下谢谢

分别说一下，不要不易理解的文话，清楚明了就行~

Answer 1

什么叫名词性从句？
在句子中起名词作用的句子叫名词从句 (Noun Clauses）
名词从句的功能相当于名词词组, 它在复合句中能担任主语、宾语、表语、同位语等，因此根据它在句中不同的语法功能，名词从句又可分别称为主语从句、宾语从句、表语从句和同位语从句

【一】主语从句 【二】表语从句 【三】宾语从句
【四】定语从句 【五】同位语从句 【六】状语从句

【一】主语从句：在主句种充当主语成分的从句叫主语从句，
引导主语从句的连词有：从属连词；连接代词；连接副词
A 从属连词：that，whether。
从属连词；that，whether引导的主语从句在主语从句中不充当任何成分,只起连接词的作用，通常不可以省略。分句置于句首时，that绝对不可以省略。如果是由It作形式主语，后面that可以省略.
1,有that 引导的主语从句如下：
1. That the driver could not control hiswar was obvious.
=It was obvious（that）the driver could notcontrol his car.
2. Thatshe was chosen made us very happy.
=it made us very happy that she was chosen
3. Thathe is still alive is sheer luck.他还活着全靠运气。
=It issheer luck that she is still alive
4. Thatthe whole project is doomed to failure is quite clear
=It isquite clear that the whole project is doomed to failure.
很清楚，整个计划注定要失败。
5. Thatyou should have to leave is a pity
=It's apity that you should have to leave.
你非走不可真是件憾事。
6. That he will refuse this piece of advice isimpossible.
=It is impossible that he will refuse this piece ofadvice
7. That they should like each other is natural
=It is natural that they should like each other
8. Thathe will not come to the meeting this evening is true
=It istrue that he will not come to the meeting this evening
9. Thathe will help others is a fact
10. That theearth turns around the sun is known to all.
=It is known to all that the earth turnsaround the sun.
11. That we can win is certain
=It is certain that we can win.
12. That you have made a mistake is a fact.
=It is a fact that you have made a mistake
13. It is ordered that we should leave at once.
14. That you don’t like him is none of my business.
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 isnecessary that…　有必要……
It is important that…　重要的是……
It is obvious that… 很明显……
It’s certain that… 肯定…
It is possible that... 很可能……
It is unlikely that... 不可能……
It is necessary \important \natural\... that…
It is possible that she will come back tomorrow.
It is obvious that this measure is effective.
b. It +be +V ed 分词+ that-从句
It is known to all that…　从所周知……
It has been decided that… 已决定……
It is said that... 据说……
It is known to all that... 众所周知……
It is reported that... 据报道……
It is believed that...据信……;人们相信……
It is suggested that + (should）do... 建议……
It must be admitted that…必须承认……
It cannot be denied that… 不可否认……
It must be pointed out that…需指出的是……
It was reported that 20 people were killed in the accident.
It was suggested that we shouldeat more vegetable and do more exercise
c. It + be +名词+ that-从句
It is a pity/shame that... 遗憾的是……
It is a surprise that…令人惊奇的是…
It is common knowledge that… …是常识
It is common knowledge that…　是常识
It is a fact that…　事实是……
It was a pity that we lost the match.
It was a fact that he cheated in the exam.
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……
It occurred to methat I forgot to send this letter
It happened that I came into the office at that time.
It is important(necessary / advisable /desirable / imperative / true / strange / possible ...)that ...需要注意的是,这类主语从句中,谓语动词很多为"(should)＋动词原形",即要用虚拟语气。例如:
It isnecessary that several nurses (should) stay.
几个护士留在这儿是很有必要的。
It isimperative that everyone (should) learn from practice.
每个人都应该从实践中学习。
It isreported (well-known / hoped / thought / expected / said / believed / decided /suggested / ordered ...)that ...例如:
It issaid that many people was killed in the earthquake.
据说很多人在这次地震中丧生了。
itseems(appears / doesn’t matter / makes no difference / ...)that ...
例如:
It makesno difference whether he will attend the meeting or not.
他是否会参加会议都无关紧要。
【二】表语从句 ：表语从句的定义：表语从句在复合句中作主句的表语。表语从句和主语指同一内容，它对主语进行解释、说明，使主语的内容具体化。
表语是用来说明主语的身份、性质、品性、特征和状态的，表语常由名词、代词、数词、动词过去分词、动词的-ing形式、副词、介词短语、形容词、不定式和从句等来充当。
Lyne is anexcellent student
Henry was anAmerican businessman
Henry met anAmerican businessman
The person stood in front of you just now is myheadmaster.
I didn’t know that it was you at that time.
The door remained closed.
Mary’s daily job is cleaning the house.
The house is not only large but also beautiful.
When I went to your house, you were out.
No one was in the dorm, when she arrived.
My job is to teach you English.
The reason why he came late was that his clockdidn’t work.
Position (位置)表语常位于系动词（be等词）之后，与主语共同构成主--系--表结构(Subject-Predicative structure) 的句子。
Linking Verbs (连系动词)
除动词be以外，还有一些后面可接表语的特殊连系动词，如：look, smell,taste, sound, feel, fall, come, go（变成…）, become, grow（渐渐地变化）, turn(变成，一般用于颜色), appear, seem,get, keep, remain, stay等。
一、表语从句定义：表语从句的定义：表语从句在复合句中作主句的表语。表语从句和主语指同一内容，它对主语进行解释、说明，使主语的内容具体化。
The question is who will do it.
表语从句放在连系动词之后，充当复合句中的表语。
二、表语从句构成
（系动词） +引导词 +简单句
His suggestion is that we should stay calm
That is why she was late.
三、引导表语从句的关联词
【1】从属连词that，whether；that 在表语从句中不充当任何句子成分，也没有任何意义。
The trouble is that I have lost her address.
麻烦是我把她的地址弄丢了。
My question is whether he left ( or not ).
我的问题是他是否离开了。
The question is whether we should ask them for help.
The trouble is that he has never done the work before
The fact is that he hasn’t yetrecover from illness.
The reason why he has to go is thathis mother is ill in bed.
比较 that在定语从句中的用法。
Thereare some films thatI’d like to see.
She isthe only student thatknows French.
结论:that 在引导定语从句时,指事物,也可指人,
在从句中作主语或宾语,作宾语时常可省略。
【2】.从属连词as, as if / though引导的表语从句
由as if 引导表语从句时要注意语态.若从句表示与现在事实相反,谓动用be 动词要用were
与过去事实相反用 had +过去分词
Li Lei is now ina new jacket.
He looks as if he were an American boy.
The girl isgiving us a vivid description of the moon.
It seems as ifshe had been to the moon many times.
He looked just ashe had looked ten years before.
It sounds as ifsomeone is knocking at the door.
It looks as if it were going to rain.
whether在表语从句中表是否 ,但不充当句子的成分。if 不能引导表语从句.如:
What the doctor really doubts is whether my mother will recover fromthe serious disease soon
【3】because, why 引导的表语从句
(1) That’sbecause he didn’t understand me.
那是因为他不理解我。(强调原因）
(2) That’s why hegot angry with me
那正是他对我生气的原因。（强调结果）
4.连接代词who, whom, whose, whoever, what,
whatever, which,whichever 引导表语从句
(1) The problemis who we can get to replace her.
问题是我们能找到谁去替换她呢。
Guilin is not whatit used to be.
What she wants to know is whichdress she should buy.
The question is what caused the accident.
That mountain is not what itused to be .
What he told you was what had been discussed at the meeting.
【4】连接副词where, when, how
The question ishow he did it.问题是他如何做此事的。
That is where he was born. 那就是他出生的地方
That is whereLu Xun used to live.
That is whyhe didn’t pass the exam.

四. 使用虚拟语气的表语从句(if不可以引导表语从句)
在表示建议、劝告、命令含义的名词后的表语从句，谓语动词需用"should+动词原形" 表示，should可省略。常见的词有：advice, suggestion, order, proposal, plan等。
My suggestion isthat we (should) start early tomorrow.
The question iswhether we will have our sports meet next week.
The reason why hefailed is that he was too careless.
The problem iswho we can get to take the place of John.
The question iswhen he can arrive at the hotel.
The question iswhether the enemy is marching towards us.
It looked as ifhe had understood this question.
The question iswho will travel with me to Beijingtomorrow.
The question iswhy he cried yesterday.
注意点1：if 不能引导表语从句
注意点2：主句主语为reason, 只能用that引导表语从句，不可用because.
注意点3：如果从句是特殊疑问句，用陈述句语序
A：表语从句一定要用陈述语序
B 不可以用if，而用whether 连接表语从句(as if 例外）。
C 不像宾语从句，在有表语从句的复合句中，主句时态和从句时态可以不一致。
【三】宾语从句：宾语从句在主从复合句中起宾语的作用，是一种名词性从句，既可作谓语动词的宾语，也可作介词、非谓语动词（动词不定式、动名词、分词.形容词）的宾语根据引导宾语从句的不同连词，宾语从句可分为三类。
1. 由that引导的宾语从句。that只有语法作用，没有实在的意义，在口语
和非正式文体中可以省略。例如：
He said (that) he wanted to stay athome.
She doesn’t know (that) she isseriously ill.
I am sure (that) he will succeed.
2. 由连接代词who, whom, whose, what, which和连接副词when, where, why, how引导的宾语从句。这些连接代词和连接副词在宾语从句中充当某个成分。例如：
Do you know who (whom) they are waitingfoe?
He asked whose handwriting was thebest.
Can you tell me where the No.3 bus stopis?
I don’t know why the train is late.
3. 由if或whether引导的宾语从句。if和whether在句中的意思是“是否”。例如：
I want to know if (whether) he livesthere.
He asked me whether (if) I could helphim.
（二）宾语从句的语序
宾语从句的语序应为陈述句的语序。例如：
I hear (that) physics isn’t easy.
I think (that) you will like thisschool soon.
Can you tell me how I can get to zoo?
Please tell me when we’ll have themeeting.
（三）宾语从句的时态
1. 如果主句的时态是一般现在时，宾语从句该用什麽时态就用什麽时态。
如： I don’t think (that) you are right.
Please tell us where he is.
Can you tell me how I can get to therailway station?
2. 如果主句的时态是一般过去时，宾语从句只能用相应的过去时态（一般过去时， 过去进行时， 过去将来时，过去完成时）。例如：
He asked what time it was.
He told me that he was preparing forthe sports meet.
He asked if you had written to Peter.
He said that he would go back to the U.S.soon.
3. 如果宾语从句所陈述的是客观真理，其时态常用一般现在时。例如：
Our teacher said that January is thefirst month of the year.
Scientists have proved that the earthturns around the sun.
4.当主句谓语动词是think、believe、imagine等时，后面的宾语从句要表示否定意义时，要通过主句的否定式来实现，即否定主句中的动词。 e.g. 我认为他明天不会来。
（wrong）I think he willnot come tomorrow.
（right）I don’t think hewill come tomorrow.
某些形容词后面也可有宾语从句,这些形容词有:sure、certain、glad、pleased、happy、afraid、surprised、satisfied等。 e.g. I’m sure you can learn English well.