what&which&引导名词性从句的区别
what that which 区别
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
It was Barcelona's sixth win in a row and, thanks to their
Brazilian's 10-goal contribution,____look like a poor season could
now end a sucess.(what/that/which)
what 和that、which比较
What I need now is to lie down and have a good rest.
我现在需要的是躺下来，好好地休息一会儿。
关系代词what与that或which不同。that与which通常代替前面的名词，并“重复其意思”：
I gave her the present which she asked for.
我给了她所要的礼物。（在此句中which代表了present）
而what 的含义则是the thing(s) that，故上句可写为：
I gave her what she asked for. (what = the present which)
what作关系代词时相当于the thing which或the thing that，故应当接一个单数形式的动词。
What we need is more motorways.
我们所需要的是更多的公路。
What& 和that
都可以引导名词性从句。但他们在句子中的语法功能截然不同。
一．在引导名词性从句时，从属连词that一般要注意三个不（three nos）：
1．不省略（no
ellipsis）
当从属连词that引导主语从句、表语从句和同位语从句时，that不省略。
Eg.& 1) That he was able
to come made us happy. (That 引导主语从句不可省略)
2)The truth is
that I didn’t go there.
(that引导表语从句不可省略)
3)The news
that our team has won is true.
(that引导同位语从句不可省略)
但在非正式文体中that
引导宾语从句时可以省略，除下列两种情况外：
that在宾语从句中不能省略的情况.
在主+谓+it(形式宾语)+宾补+that， 从句(真正宾语)
的句型中不省略.
&Eg:& 4) He
made it quite clear that he preferred to study
English.（that不可以省略）
他很明确地说他宁愿学习英语。
(2).& 由连词and连接的两个由that引导 的宾语从句中, 则第二个宾语从句前的that不省略。
He told me that he would come and that he would come on
time.（第一个That可以省略，但第二个that不可以省略。)他告诉我他将来而且他将准时来。
2．不作成分（no
component）
在名词性从句中不作任何句子成分。
Eg.&& 6)Sydney
kept his promise that he would always do anything he could
for Lucie to make sure of her happiness.（that在句中引导同位语从句，但在句中不作任何成分）
7))That you don’t like him is none of my business.
(that在句中引导主语从句，但在句中不作任何成分，也不省略）
3．& 没词义（no meaning）
在名词性从句中没有汉语意思。
Eg.&& 8)That
she is a rich woman is known to us.
(that在句中引导主语从句，但在句中没有汉语意义)
她是一个很有钱的女子，这一点我们都知道。
9）The thought that he might
fail in the exam worried him.
(that在句中引导同位语从句，但在句中没有汉语意义）
他也许会考试失败，这一想法使他很担心。
二．在引导名词性从句时，What一般要注意一个不（one no）,一个有（meaning）,一个作（component）：
引导名词性从句时，what
在句中不省略。这一用法与that
用法不尽相同。
What I had for breakfast today was rice with
egg.(what 在句中引导主语从句，what
11)----I think it’s going to be a big problem.
----Yes , it could be .
----I wonder& what we can do about.
(what在句中引导宾语从句，但在句中不省略）
引导名词性从句时，有词义。一般是“----的东西/事情/话等”这一用法与that 用法不一样
eg.& 1) This is what she
wanted to show us. (what在句中引导表语从句，在句中有词义，意思是“----的东西、事情）这是她想让我们看的东西。
12）What the teacher said
had a good effect on the children.
(what在句中引导主语从句，在句中有词义，意思是“----的东西、事情）老师所说的话对孩子们有很好的作用。
在引导名词性从句时，在从句中充当成分。这一用法与that
用法不一样。
Eg.& 13)It doesn’t matter
what he said.( it 是形式主语，what 在句中引导主语从句。What 在主语从句中作said 的宾语。)
14）It was true ______Alice did
surprised her mother.
what& B. what that& C.
that& that& D. all
评析：这一题正确答案是A。it在句中是形式主语，that引导的是主语从句that Alice did surprised her
mother.，在这个主语从句当中，what
又引导了主语从句what Alice
did，what在从句中作did 的宾语。
三．要特别提醒同学们的两点：
What所引导的从句可以在介词后作宾语，而that从句一般不可以。
15）After months of voyage
,Columbus arrived in _____later proved to be a new
continent.
where&& B.
which&&& C.
what&&& D.
评析：答案是C。因为在介词in 后面，应该用what引导的宾语从句，what在宾语从句中作主语。而that不可以这样用。
16) On stepping into his room, he was astonished to find the floor
covered with _____looked like tiny insects.
A. that& B. something&
C.& what& D.
&评析：答案是C。因为在介词with 后面，应该用what引导的宾语从句，what在宾语从句中作主语。而that不可以这样用。
2.that可以引导定语从句，而且是定语从句引导词中的顶梁柱，它在定语从句中要充当成分，通常作定语从句中的主语、宾语。同时that也可以引导名词性从句，在名词性从句中that
不充当成分。 但What不可以引导定语从句。它只可以引导名词性从句,在句中相当于 what
=all that ,what 在名词性从句中充当成分，常常作主语、宾语和表语。
17).All _____I want to know is what he meant .
that& B. which& C.
what& D. whatever
评析：答案是A.本题是that引导的定语从句。而what不可以引导定语从句。What=all that .又因为先行词是all ，故其后不可以接which 引导的定语从句。而. Whatever=anything that /no matter what
从意义和语法都不符合。所以只能选A,that.
18) ______impressed me most was ______such a little boy could play
the violin so well.
A. T what& B. W that&
C. T that& D. W what
评析：答案是B.第一空是what 引导的主语从句，并在主语从句中作主语。第二空是that 引导的表语从句，that在表语从句中不省略，不作成分，也没词义。
要真正掌握What& 和that 在名词性从句中的用法，还得多多操练,熟能生巧（Practice makes perferct
注意！！定语从句的连接词不可以用what．
一.定语从句及相关术语
1.定语从句：修饰一个名词或代词的从句称为定语从句，一般紧跟在它所修饰的先行词后面。
2.关系词：引导定语从句的关联词成为关系词
关系词有关系代词和关系副词。关系代词有that, which, who, whom, whose, as 等；
关系副词有where, when, why等。
关系词常有3个作用：1，引导定语从句。2，代替先行词。3，在定语从句中担当一个成分。
二.关系代词引导的定语从句
1.who指人，在从句中做主语
(1) The boys who are playing football are from Class One.
(2) Yesterday I helped an old man who lost his way.
2. whom指人，在定语从句中充当宾语，常可省略。
(1) Mr. Liu is the person (whom) you talked about on the bus.
(2) Mr. Ling is just the boy whom I want to see.
注意：关系代词whom在口语和非正式语体中常用who代替，可省略。
(3) The man who/whom you met just now is my friend.
3. which指物，在定语从句中做主语或者宾语，做宾语时可省略
(1) Football is a game which is liked by most boys.
(2) This is the pen (which) he bought yesterday.
4. that指人时，相当于who 或者whom；指物时，相当于which。在宾语从句中做主语或者宾语，做宾语时可省略。
(5) The number of the people that/who come to visit the city each
year rises one million.
(6) Where is the man that/whom I saw this morning?
5. whose通常指人，也可指物，在定语从句中做定语
(1) He has a friend whose father is a doctor.
(2) I once lived in a house whose roof has fallen in.
whose指物时，常用以下结构来代替
(3) The classroom whose door is broken will soon be repaired.
(4) The classroom the door of which is broken will soon be
(5) Do you like the book whose cover is yellow?
(6) Do you like the book the color of which is yellow?
三.介词+关系代词引导的定语从句
关系代词在定语从句中做介词宾语时，从句常由介词+关系代词引导
(1) The school (that/which) he once studied in is very
(2) The school in which he once studied is very famous.
(3) Tomorrow I will bring here a magazine (that/which) you asked
(4) Tomorrow I will bring here a magazine for which you
(5) We'll go to hear the famous singer (whom/that/who) we have
often talked about.
(6) We'll go to hear the famous singer about whom we have often
注意：1. 含有介词的动词短语一般不拆开使用，如：look for, look after, take care of等
(1) This is the watch which/that I am looking for. (T)
(2) This is the watch for which I am looking. (F)
若介词放在关系代词前，关系代词指人时用whom，不可用who或者that；指物时用which，不能用that；关系代词是所有格时用whose
(1) The man with whom you talked is my friend. (T)
(2) The man who/that you talked with is my friend. (F)
(3) The plane in which we flew to Canada is very comfortable.
(4) The plane in that we flew in to Canada is very comfortable.
3.“介词+关系代词”前可有some, any, none, both, all, neither, most, each,
few等代词或者数词
(1) He loved his parents deeply, both of whom are very kind to
(2) In the basket there are quite many apples, some of which have
(3) There are forty students in our class in all, most of whom are
from big cities.
四．关系副词引导的定语从句
1. when指时间，在定语从句中做时间状语
(1) I still remember the day when I first came to the school.
(2) The time when we got together finally came.
2. where指地点，在定语从句中做地点状语
(1) Shanghai is the city where I was born.
(2) The house where I lived ten years ago has been pulled
3. why指原因，在定语从句中做原因状语
(1) Please tell me the reason why you missed the plane.
(2) I don't know the reason why he looks unhappy today.
注意：关系副词引导的从句可以由“介词+关系代词”引导的从句替换
(1) The reason why/ for which he refused the invitation is not
(2) From the year when/in which he was going to school he began to
know what he wanted when he grew up.
(3) Great changes have taken place in the city in which/where I was
五．限制性定语从句和非限制性定语从句
限制性定语从句举例：
(1) The teacher told me that Tom was the only person that I could
depend on.
(2) China is a country which has a long history.
非限制性定语从句举例：
(1) His mother, who loves him very much, is strict with him.
(2) China, which was founded in 1949, is becoming more and more
要注意区分以下几个句子的不同
(1) His brother who is now a doctor always encourages him to go to
他那当医生的哥哥常鼓励他要考上大学。（他还有其他的哥哥）
(2) His brother, who is now a doctor, always encourages him to go
to college.
他的哥哥是当医生的，常鼓励他要考上大学。（他只有一个哥哥）
（一）限制性定语从句只能用that 的几种情况
1．当先行词是anything, everything, nothing (something 除外), few, all,
none, little, some 等代词时，或者是由every, any, all, some, no, little, few,
much 等修饰时
(1) Have you taken down everything that Mr. Li has said?
(2) There seems to be nothing that seems impossible for him in the
(3) All that can be done has been done.
(4) There is little that I can do for you.
注意：当先行词指人时，偶尔也可以用who
(4) Any man that/.who has a sense of duty won't do such a
2. 当先行词被序数词修饰
(1) The first place that they visited in London was the Big
3. 当先行词被形容词最高级修饰时
(1) This is the best film that I have seen.
4. 当形容词被the very, the only修饰时
(1) This is the very dictionary that I want to buy,
(2) After the fire in his house, the old car is the only thing that
当先行词指人时，偶尔也可以用who
(3) Wang Hua is the only person in our school who will attend the
5. 当先行词前面有who, which等疑问代词时
(1) Who is the man that is standing there?
(2) Which is the T-shirt that fits me most?
6. 当先行词既有人，也有动物或者物体时
(1) Can you remember the scientist and his theory that we have
（二）关系代词as和which 引导的定语从句
as和which引导非限制性定语从句，有相同之处也有不同之处。具体情况是：
1．As和which都可以在定语从句中做主语或者宾语，代表前面整个句子。
(1) He married her, as/which was natural.
(2) He was honest, as/which we can see.
as引导非限制性定语从句，可放在主句之前，或者主句之后，甚至可以切割一个主句；which引导的非限制性定语从句只能放在主句之后。另外，as有“正如……，正像……”的意思
(1) As is known to all, China is a developing country.
(2) He is from the south, as we can see from his accent.
(3) John, as you know, is a famous writer.
(4) He has been to Paris more than several times, which I don't
注意：当主句和从句存在逻辑上的因果关系时，常用which
(5) Tom was always late for school, which made his teacher
3. 当先行次受such, the same修饰时，常用as
(1) I have never heard such a story as he tells.
(2) He is not such a fool as he looks.
(3) This is the same book as I lost last week.
注意：当先行次由the same修饰时，偶尔也用that引导定语从句，但是和由as 所引导的定语从句意思不同
(4) She wore the same dress that she wore at Mary's wedding.
她穿着她在Mary婚礼上穿过的一条裙子。
(5) She wore the same dress as her young sister wore.
她穿着和她妹妹所穿的一样的裙子。
（三）以the way为先行词的定语从句通常由in which, that引导，而且通常可以省略。
(1) The way in which/ that/./ he answered the question was
surprising.
(四) but 有时也可以做关系词引导定语从句
(1) There are very few but understand his idea. ( but= who don't
(五)区分定语从句和同位语从句
1．定语从句修饰先行词，它和先行词是修饰关系；同位语从句说明先行词的具体内容，是补充说明的关系
(1) The plane that has just taken off is for London. 定语从句
(2) The fact that he has been dead is clear. 同位于从句
2．定语从句由关系代词或者关系副词引导，关系词在句中充当成分，有时可以省略；同位语从句主要由that引导，在句中一般不做成分；句子也可以由when,
where, how, why, whether, what等词引导，充当成分
(1) The news he told me is true.
(2) The news that he has just died is true.
(3) The problem that we are facing now is how we can collect so
much money. 定语
(4) The problem how we can collect so much money is difficult to
3. 同位语从句和先行词一般可以用be动词发展成一个完整的句子，而定语从句不可以
(1) The idea that we could ask the teacher for advice is
wonderful.
(2) The idea was that we could ask the teacher for advice.
(3) The fact that the earth moves around the earth is known to all.
(4) The fact is that the earth moves around the
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英语 定语从句which 和what 后面所接的东西有什么区别?
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参考下链接定语从句：指人时常用which 和 who 而 what 则常用于指物首先你要区分从句的概念,定语从句不是名词性从句.名词性从句分为：主语从句,宾语从句,同位语从句和表语从句.what可以引导名词性从句,在从句中可做主语、宾语、表语.which是关系代词,引导定语从句,在从句中可充当主语、宾语、表语.引导定语从句的词分为关系代词（which,that,who,whom,whose,as）关系副词（when,where,why）,注意：没有what.简单点记吧：定语从句放在表示“事物”的名词后面,且关系代词在从句中充当句子成分,用which.如果不是定语从句,就考虑用what.如：1.This is the book which I talked about yeasterday.(which引导定语从句放在名词book后面起修饰作用,which在从句中充当talk about的宾语)2.This book is what I talked about yesterday.(what引导名词性从句,放在is之后,what 在表语从句（名词性从句）充当talked about的宾语.)
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　　单词辨析 知识讲解 　what,which,that,how的用法
　　what,which,that,how的用法。
　　连接词
　　这几个词都可以引导名词性从句。
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引导主语从句且在句首，如：Whether&he&will&come&is&not&clear.&
&&&&&2.&引导表语从句&
&&&&&3.&whether从句作介词宾语&4
&&&&&从句后有&or&not&&&&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、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…&&&众所周知……&&&&
&&&&&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……&
&&&&&三、&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。&
&&&&&四、&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待证实。&
&&&&&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whether…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。&
&&&&&五、&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。
　　连接词
　　这几个词都可以引导名词性从句。
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引导主语从句且在句首，如：Whether&he&will&come&is&not&clear.&
&&&&&2.&引导表语从句&
&&&&&3.&whether从句作介词宾语&4
&&&&&从句后有&or&not&&&&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、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…&&&众所周知……&&&&
&&&&&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……&
&&&&&三、&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。&
&&&&&四、&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待证实。&
&&&&&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whether…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。&
&&&&&五、&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。