(完整版)高考名词性从句详解.doc
(完整版)名词性从句讲解及专项练习习题及其解答

名词性从句讲解在复合句中起名词作用的从句叫做名词性从句。
它包括主语从句、宾语从句、表语从句和同位语从句。
名词性从句是中学阶段的一个重要语法项目,在历年的高考中几乎都涉及到,并且每年的命题各有变化。
分析历届高考试题名词性从句考查的焦点主要有以下六个方面1. 考查名词性从句的语序问题2. 考查引导词that与what的区别3. 考查it在名词性从句中作形式主语或形式宾语的用法4. 考查whether与if的区别5. 考查名词性从句中的疑问词+ever引导的名词性从句与no matter+疑问词引导的状语从句的区别6. 考查名词性从句的虚拟语气问题语法要点剖析一、名词性从句主语从句、表语从句、宾语从句、同位语从句,在整个句子中所起的作用,相当于一个名词。
因此,这四种从句通称为名词性从句。
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, why1. 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。
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。
(完整word版)高考名词性从句知识点总结,推荐文档

名词性从句主语从句宾语从句名词性从句表语从句同位语从句以that引导以whether/if引导名词性从句结构以特殊疑问句引导以what或wh-ever等连接代词引导(名词性关系从句)一、主语从句1.以that引导的主语从句That从句作主语时,常用it作形式主语①it + be + 形容词(obvious, true, natural, surprising, good, wonderful,funny, possible, likely, certain, probable…)+ that从句②it + be + 名词词组(no wonder, an honor, a good thing, a pity, nosurprise…)+ that从句③it + be + 过去分词(said, reported, thought, expected, decided…)+ that从句即形容词/名词词组/过去分词形式主语真正主语在口语和非正式文体中,that可省略,尤其很短的句子,that不必要,但是that从句位于句首时,that绝不可省略2.whether引导的主语从句强调主语从句谓语句首只能用whether,不可用if代替主语从句在句末,whether和if均可3.特殊疑问词引导的主语从句常用it作形式主语连接代词who, which和连接副词when, where, how, why都可引导主语从句,不可省如句子是疑问句式,则必须用it引导4.名词性关系从句(以what或wh-ever等连接代词引导的名词性关系从句)what或wh-ever引导主语从句【例】What they need is a good textbook.Whichever he likes will be given to him二、宾语从句1.以that引导的宾语从句常见的可以接that从句作宾语的动词有:see, say, know, imagine, discover,believe, tell, show, think, consider, be sure, be afraid等,在可以接复合宾语的动词之后如think, make, consider等,可以用it作形式宾语That从句一般不能充当介宾,偶尔可做except,in的宾语【例】he is a good student except that he is a little bit careless2.whether/if 引导的宾语从句whether从句中不能有否定式介词后只能用whether,不能用if3.特殊疑问词引导的宾语从句能接特殊疑问词引导的宾语从句的动词很多,例如see, tell, ask, answer,know, decide, find out, imagine, suggest, doubt, wonder, show, discuss,understand, inform, advise等4.名词性关系从句(作动宾,介宾)三、表语从句1.that引导表语从句that 不可省略My ides is that we’ll all go except him.That是连词,在句中不充当成分,没有意义,不可省略2.Whether引导表语从句只能用whether,不能用if注:从属连词if一般不用来引导表语从句,但是as if却可以3.特殊疑问词引导表语从句注意从句用陈述语序The problem is where we should stay.4.名词性关系从句注意从句用陈述语序Tomorrow is when it would be most convenient.四、同位语从句1.that引导的同位语从句应在某些抽象名词后,如fact, hope, desire, thought, suggestion, idea, news,problem, possibility,对前面的名词起补充说明作用,在从句中不充当任何成分,但不可省略。
名词性从句(整理完整版)

名词性从句一、定义:名词性从句在功能上相当于名词,是一个句子分别充当另一个句子的主语、表语、宾语和同位语,由此被称为主语从句,表语从句,宾语从句和同位语从句。
辨别下列从句属于哪种名词性从句并分析:1)Why they haven’t left yet is unclear.2)It was good news that everyone got back safely.3)Polly didn’t know which way she should go.4)I’m interested in who that tall man is.5)We all thought it good news that the fog had finally gone.6)My question is whether Polly can find her way home.7)The fact that Polly didn’t ask for the man’s name is a pity.总结:名词性从句主要由陈述句、一般疑问句、特殊疑问句充当。
1)陈述句充当名词性从句时,由that引导;2)一般疑问句充当名词性从句时,由if或whether引导从句;3)特殊疑问句充当名词性从句时,由疑问词本身做连词引导从句。
4)名词性从句的语序应使用陈述句语序,不可用一般问句语序。
二、引导名词性从句的从属连词及从句语序1.连接词that;功能1)不充当句子成分2)无词义3)只起连接作用。
2.if/whether;功能:1)意为“是否”,有词义2)不做句子成分3)起连接作用翻译:1)I know that he will come thisevening.___________________________________________2) Whether we will go there or not hasn’t been decided yet.______________________________3.连接代词:what(ever), which(ever), who(ever), whom(ever), whose(ver)功能:1)有词义2)引起从句3)且在从句中充当一定的句子成分,常做从句中的主语、宾语、表语和定语。
高考英语复习 名词性从句讲解

名词性从句一、名词性从句与简单句的区别在英文中,名词或名词短语主要充当四种句子成分:主语、宾语、表语和同位语。
如果把句子当作名词来用,分别充当另一句话的主语、宾语、表语或同位语,于是便构成了四种从句:主语从句、宾语从句、表语从句和同位语从句。
因为这四种从句在本质上相当于名词的作用,所以将其统称为名词性从句。
请看下表:在英语中,相当于名词作用的句子有三类,陈述句、一般疑问句以及特殊疑问句。
因此,名词从句就是用三种句子来分别充当另外一个句子的四种句子成分,者就构成了名词从句的本质特征。
但是,这三种句子不是直接放在另一个句子中作成分,而是要作各种变化调整。
接下来将具体讨论。
二、陈述句作句子成分1. 要在陈述句句首加上t hat用”that+陈述句”这一结构分别充当另一个句子的四种成分。
2.为什么要加that?对于陈述句,为什么要在其句首加that 后才能用它作成分呢?而为什么在宾语从句中that 又可以省去呢?因为在英文中,句子的核心意思主要是靠谓语部分来表达,一个句子只表达一个核心意思,也就是只能有一个谓语部分。
而添加that,相当于一个“指路牌”,能够帮助我们指明段句的方向,而不至于造成歧义。
而对于宾语从句,主句的谓语已经出现,后面所接的成分自然是谓语,所以在不会影响句子的意思下,是可以把that 省去的。
三、一般疑问句作句子成分1.用w hether 或if 引导先将疑问句的倒装语序变成陈述句语序(即主语放在谓语的前面),并在句首加上whether 或if(if 只用在宾语从句中)来引导,以保留原句的疑问意义。
即“whether+陈述句”2. if 还是 whether?1)if 一般只用于引导宾语从句,而 whether 可引导宾语从句在 内的其他名词从句。
IF he comes or not makes no difference. 成 Whether he comes or not makes no difference.2)if 不和 or not 直接连用,即一般不说 if or not, 但可以说 if...or not 。
高考英语名词性从句专题(精辟)

名词性从句的考查要点:(1) What ,that 引导名词性从句的区别; (2) Whether ,if 引导名词性从句的区别; (3) 同位语从句和定语从句的区别; 一、 名词性从句概述在句子中起名词作用的句子叫名词性从句(Noun Clauses )。
名词性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、和同位语,因此根据它在句中充当不同的语法功能,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。
二、名词性从句比较请注意1、名词性从句中的that 省略情况:动词后的宾语从句和表语从句中的that 可以省略。
2、No matter +wh-开头的词如no matter what 等只能连接让步状语从句。
而wh-开头的词+ever 如whatever 等既能连接让步状语从句,也能连接名词性从句。
解题步骤和原则:分析复合句结构,找出从句,确定名词性从句中的哪一类。
分析从句,结合上表中各个连接词的特点,缺什么补什么。
主语从句中It 作形式主语常用句型:1.It + be +形容词(obvious, true, natural, possible, likely, probable, certain, wonderful, good, etc.) + that 从句2. It + be +名词词组(no wonder ,a pity ,an honor, a good thing, no surprise , etc.) + that 从句3. It + be + 过去分词(said, thought, reported, expected, announced, decided , etc.) + that 从句4. It +不及物动词(seem, happen, etc.) + that 从句5. It doesn ’t matter(make no different , etc.) + 连接代词或连接副词引导的主语从句Eg: It is certainthat she will do well in her exam. Eg1.(2012课标·全国I) It is by no means clear__________ thepresident can do to end the strike.A.howB. whichC. thatD. what2.(2012天津,7)It doesn’t matter _______you turn right or left at the crossing — both roads lead to the park.A. whetherB. howC. ifD. when3.(2012江西,25) It suddenly occurred to him_________ he had left his keys in the office.A. whetherB. whereC. whichD. that1. if /whether表示“是否” 可以互换,但以下情况只能用whether,不用if. (1)在介词后面Eg:Everything depends on whether we have enough time.(2)与or not连用Eg:I don’t know whether he will come or not.(3)宾语从句提前时Eg:whether they can come here on time, we don’t know.(4)后面跟不定式Eg:I really don’t know whether to accept or refuse.2. 宾语从句的时态(一般来说,主从句时态要统一。
高考英语一轮复习——名词性从句(附答案)

高考英语一轮复习——名词性从句(附答案)I. 考点分析名词性从句包括:主语从句、宾语从句、表语从句、同位语从句,多由连词that,wh- 疑问词或由what,whatever等关系代词引导,其中同位语从句在高考考试中最常见。
1. 主语从句1) 主语从句在句子中充当主语,句子的谓语动词用第三人称单数。
如:Why he refused to work with you is still mystery.Whoever comes is welcome.2) 主语从句前的that不能省略,仅起连接作用,有时为了保持句子平衡,that从句后置,而由it作形式主语。
如:That he became a lawyer may have been due to his mother’s influence.It is not true that he has moved to New York.2. 宾语从句在句子中充当宾语,如:I don’t know where the sound came from.Don’t be satisfied with what you have achieved.3.当从句放在系动词be, look, remain, seem等后即构成表语从句。
The trouble is that I have lost his address.It seemed that the night would never end.4. 1) 同位语从句是对与之同位的名词中心词作进一步解释,能接名词性从句的常见名词有: idea, fact, news, belief, hope, evidence, opinion, problem, truth, answer, proposal, theory, decision, discovery, problem, thought, understanding 等。
(完整版)高中英语名词性从句详解

(完整版)高中英语名词性从句详解名词性从句【名词性从句】相当于名词,可分别作主句的主语、表语、宾语和同位语。
因此,名词性从句分为主语从句、表语从句、宾语从句和同位从句。
宾语从句——在复合句中作主句及物动词的宾语,也可作介词或某些形容词的宾语1。
连接词从属连词that whether if 不担任成分只起连接作用关系代词who whom whose whatwhich既担任成分,又起连接作用。
主语,宾语或表语等关系副词when where why how 既担任成分,又起连接作用常担任状语◆I think (that) you will like the pictures。
◆ He has become what he wanted to be ten years ago。
◆ I don't know why Jane was late for school this morning。
◆The teacher is pleased with what she said。
◆I’m afraid that I can’t go to the party。
2.注意事项(that通常可以省略)。
但如从句是并列句时,第二个分句前的that 不可省。
◆He told me (that) he was ill and that he would not come to the party。
②陈述语序◆ I want to know what he has told you。
◆ She will give whoever needs help a warm support。
③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。
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。
高考英语复习语法知识专题讲解15---名词性从句(解析版)

高考英语复习语法知识专题讲解专题十专题十五五 名词性从名词性从句句名词性从句的句法功能相当于名词词组,在句中充当主语、宾语、表语、同位语、介词宾语等。
因此名词性从句又分为主语从句、宾语从句、表语从句和同位语从句。
类别功 能 引 导 词 从属连词只起连接作用,不充当句子成分 that, whether, if 连接代词 起连接作用,并充当主语、宾语、表语或定语 who, whom, whose, which, what, whatever, whichever,whoever连接副词 起连接作用,并充当从句状语when, where, how, why 一、主语从句的易错点主语从句的一般结构主语从句+谓语动词+其他 How the book will sell depends on its author. That he is the best student in the class is obvious.it 作形式 主语时的主语从句 It+be/becomes/became+形容词/名词/过去分词+主语从句 It is still a question whether she will come or not. It became clear that Mary did make a mistake. It seems/ appears/ happens 等动词+that 从句 It seems strange that he should have done a thing like that. It happens that he can understand a little about thelanguage. It remains to be+过去分词+主语从句It remains to be seen who will be the victor in the contest.It doesn't matter +how/whether 从句 It doesn't matter whether he is wrong or not.It doesn't matter much whether we go together orseparately.用来表示惊奇、怀疑、惋惜、理应如此等语气时,主语从句谓语动词用(should) do 形式 It is necessary /important / natural /strange 等+that 从句It is necessary that one(should)obey the law.It is suggested /requested /proposed/desired 等+that 从句It is suggested that you (should) attend the openingceremony.二、宾语从句的易错点动词后的宾语从句主语+及物动词+宾语从句I know that he is an honest boy.Can you tell me how I can get to the zoo?I wonder if/whether you have told the news to Li Lei.They asked what Jean was doing now.Do you know who has won Red.Alert game?feel, think, find, consider, make等,常用it作形式宾语,宾语从句后置I find it important that.we should keep calm in danger.You may think it strange that he would live there.I feel it a pity that I haven't been to the get-together.I have made it a rule that I keep diaries.like, dislike, love, hate, enjoy,appreciate等不能直接跟宾语从句,必须用it作形式宾语,后接宾语从句I like it that everyone passed the exam.I hate it when they talk with their mouths full of food.think, believe, suppose, 等词后的宾语从句若是否定的,否定词要转移到主句的谓语动词上I don't think your answers are right.I don't believe that man is killed by Jim, is he?介词后的宾语从句介词后可接宾语从句,但连接词whether 不可换作ifHe often thinks of how he can make his class lively.She worries about whether she's really good enough.非谓语动词之后的宾语从句不定式、v.-ing形式、过去分词后也可以接宾语从句I'd just tried to do what I could for you.I suggest eating what is fresh.宾语从句中的时态主句谓语动词为一般现在时,从句时态根据实际情况而定Do you know when the ancient games began?主句谓语动词是一般过去时,从句的时态一般用适当的过去时态He asked me if I was reading the textbook when he wasin.当宾语从句为客观真理和规律时,则用一般现在时He said that light travels faster than sound.whether与if 引导宾语从句的区别与 or not 连用时,只用 whether I want to know whether or not the train goes to KingStreet."whether+不定式”结构作宾语,相当于一个宾语从句;if无此用法I don't know whether to go there.介词后面的宾语从句中只用whetherI'm not interested in whether he has a lot of money.if引导的条件句中,如果再有表示“是否”的引导词引导宾语从句时,只用 whetherHe asked me whether I'd move to Beijing if I got the job.doubt 在肯定句中,接whether 和if引导的宾语从句;但在否定句中,只用 thatWe don't doubt that he is a brave man.I doubt whether/if Jack could manage a sailing boat.三、表语从句的易错点表语从句常位于连系动词be, look, remain, seem等之后,其连接词还有as if/though,because等主语+系动词+表语从句The trouble is that we are short of money.He looked just as he had looked ten years before. The question is whether they will be able to help us. The problem is who we can get to replace her.I think it is because you are doing too much.The question is which of us should go.because 引导表语从句强调原因,why引导表语从句强调结果It's because you're careless.That is why stone walls are used instead of fences around New England fields.the reason why 从句+be + that 从句The reason why he was absent was that he was ill.what 从句+be+that从句What comforted the young mother was that the babycame to life.It looks/seems as if/though 从句It looks as if it is going to rain.At that time, it seemed as if I couldn't think of the right word anyhow.主句主语是advice, demand, suggestion, order,requirement, idea, request,command等时,表语My advice is that you(should)quit smoking.从句用虚拟语气,即谓语动词用(should)do 形式My suggestion is that we(should)start early tomorrow. Our only request is that this(should)be settled as soon as possible.四、名词性从句其他易错点that与what 在名词性从句中的区别what 充当成分,意为...的事物不可省略;that 不作任何成分,只起连接作用,也无实际意义,有时可以省略I only knew(that)he was studying in a western country,butI didn't know what country he was in.What you need is more practice.That you will win the medal seems unlikely.名词性从句已有疑问引导词时,不再用thatI don't understand what you said just now.(understand 后不再用 that)2021高考英语语法高考英语语法【【名词性从句名词性从句】】易错点对点训练30题I.高考真题诊断·单句语法填空1.Every year, makes the most beautiful kite will win a prize in the Kite Festival.2.She asked me I had returned the books to the library, and I admitted that I hadn't.3.The manager put forward a suggestion we should have an assistant. There is too much work to do.4.As natural architects,the Pueblo Indians figured out exactly thick the adobe walls needed to be to make the cycle work on most days.5.If you swim in a river or lake,be sure to investigate is below the water surface.Often there are rocks or branches hidden in the water.【答案详解】1.whoever解析:句意:每年,无论谁做出最漂亮的风筝都将会在风筝节获奖。
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
高考名词性从句目录一、引导名词性从句的连接词二. 主语从句三、宾语从句四、表语从句五.同位语从句六、名词性 that-从句七、名词性 wh-从句八、否定转移九、高考热点透视十、专项考点练习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、引导名词性从句的连接词名词性从句引导词的分类引导词 常见引导词补充说明的类别that ;if 、whether that 无意义,不充当句子成分, If ,whether 表是否,不充当句 连词as if ,as though (均表只起连接作用,引导宾语从句 子成分,只起连接作用,位于好像、似乎) 可省略句首时只用 whether what whateverwhich whichever What 不引导定语从句,引导的名词性从句其意义相当于连接代词who whoever “名词 +定语从句”。
whom whomever 连接代词有词义,在句中担任主语,表语,定语或宾语whose whoseverwhenwhenever 有词义,在句中担任状语。
什么时候 什么地wherewhere, 连接副词whereverwhen ,how 方 why, 为什么 how ,怎么样howeverwhy二. 主语从句What he wants to tell us is not clear.Who will win the match is still unknown.Where the English evening will be held has not yet been announced.注意: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 从句当堂练习:(1)It is immediately clear ____ the financial crisis will soon be over.( 2) ____ was most important to her, she told me, was her family. ( 3)watch was lost is unknown.( 4)he finished writing the composition in such a short time surprised us all.三、宾语从句We must never think (that) we are good in everything while others are good in nothing. He has told me that he will go to Shanghai tomorrow.(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。
)I want to know what he has told you.注意:当 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 ’tthink you are here. 我们认为你不在这。
I don’tbelieve he will do so. 我相信他不会这样做。
当堂练习:(1) The companies are working together to create _______ they hope will be the best means of transport in the 21st century.( 2) She always thinks of she can work well.( 3) She will give needs help a warm support.四、表语从句The fact is that we have lost the game.That’sjust what I want.The reason why he was late was that he missed the train by one minute this morning .当堂练习:(1)The last time we had great fun was _______ we were visiting the Water Park.(2)He has become he wanted to be ten years ago.(3)You are saying that everyone should be equal, and this is ____ I disagree.五. 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。
The news that we won the game is exciting.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.当堂练习:We should consider the students’request ________ the school library provide more books on popular science.六、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(纯粹的 ) 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,整个划注定要失。
It's a pity that you should have to leave.你非走不可真是件憾事。
用it 作形式主的 that-从句有以下四种不同的搭配关系: a.It + be +形容 + that-从句It is necessary that⋯有必要⋯⋯It is important that ⋯重要的是⋯⋯It is obvious that⋯很明⋯⋯b. It + be + -ed 分 + that-从句It is believed that⋯人相信⋯⋯It has been decided that⋯已决定⋯⋯c. It + be +名 + that-从句It is common knowledge that⋯⋯⋯是常It is a surprise that⋯令人惊奇的是⋯⋯It is a fact that⋯事是⋯⋯d. It +不及物 + that-分句It appears that⋯似乎⋯⋯It happens that⋯碰巧⋯⋯It occurred to me that ⋯我突然想起⋯⋯七、名词性 wh-从句1)由wh-引的名从句叫做名性wh-从句。
Wh-包括 who, whom,. whose, whoever, what,whatever, which, whichever 等接代和 where, when, how, why 等接副。
Wh-从句的法功能除了和 that- 从句一外,可充当介、和接等,例如:主: How the book will sell depends on its author.售如何取决于作者本人。
直接: In one's own home one can do what one likes. 在自己家里可以随心所欲。
接: The club will give whoever wins a prize.俱部将得者。
表: My question is who will take over president of the Foundation. 我的是将接任基金会主席位。
足:She will name him whatever she wants to. 她高他起什么名字就取什么名字。
同位:I have no idea when he will return.我不知道他什么候回来。
形容: I'm not sure why she refused their invitation.我尚不能肯定她什么拒他的邀。
介:That depends on where we shall go.那取决于我去哪儿。
2) Wh-从句作主也常用先行it 做形式主,而将wh-从句置于句末,例如:It is not yet decided who will do that job.没决定做工作。