一、理解同位语从句的含义，把握同位语从句的实质
在主从复合句中作同位语的从句称为同位语从句。同位语从句一般用that, whether，what, which, who, when, where, why, how 等词引导，常放在fact, news, idea, truth, hope, problem, information, wish,promise, answer, evidence, report, explanation, suggestion, conclusion等抽象名词后面，说明该名词的具体内容。换言之，同位语从句和所修饰的名词在内容上为同一关系，对其内容作进一步说明。
例：The news that they had won the game soon spread over the whole school.他们比赛获胜的消息很快传遍了整个学校。
析：they had won the game说明The news的全部内容，因此该句为同位语从句。
二、正确运用同位语从句的引导词，准确把握同位语从句
1.如同位语从句意义完整，应用that引导同位语从句。（即that 不充当任何成分，只起连接作用，不可省略）
例：The general gave the order that the soldiers should cross the river at once.将军下达了战士们立即过河的命令。
析：the soldiers should cross the river at once是the order的全部内容，且意义完整，因此应用that引导同位语从句。
2.如同位语从句意义不完整，需增加"是否"的含义，应用whether引导同位语从句。（if不能引导同位语从句）
例：We'll discuss the problem whether the sports meeting will be held on time.我们将讨论运动会是否会如期举行的问题。
析：the sports meeting will be held on time意义不完整，应加"是否"的含义才能表达the problem的全部内容，因此应用whether引导同位语从句。
3.如同位语从句意义不完整，需增加"什么时候"、"什么地点"、"什么方式"等含义，应用when, where, how等词引导同位语从句。
例1：I have no idea when he will be back.
析：he will be back意义不完整，应加"什么时候"的含义才能表达idea的全部内容，因此应用when引导同位语从句。
例2：I have no impression how he went home, perhaps by bike. 析：he went home意义不完整，应加"如何"的含义才能表达impression的全部内容，因此应用how引导同位语从句。
4.当主句的谓语较短，而同位语从句较长时，同位语从句常后置。
如：The thought came to him that maybe the enemy had fled the city.
三、把握同位语从句和定语从句的区别
明确同位语从句和相似从句的界限 同位语从句和定语从句相似，都放在某一名词或代词后面，但同位语从句不同于定语从句。同位语从句对名词加以补充说明，是名词全部内容的体现，且名词和同位语从句的引导词均不在从句中作成分；定语从句说明先行词的性质与特征，与先行词是修饰与被修饰的关系，且名词和定语从句的引导词均在从句中作成分。
区分时可以在先行词与与从句之间加一个系动词be,使之构成一个新句子，如果句子通顺且符合逻辑，则为同位语从句，反之，则为定语从句。
如：The report that he was going to resign was false.
因为the report was that he was going to resign 句意通顺，所以，that he was going to resign 是同位语从句。
例1：
1）Information has been put forward ____ more middle school graduates will be admitted into universities.
A. while B. that C. when D. as
析：答案为B。more middle school graduates will be admitted into universities是Information的内容，且Information不在从句中作成分，所以该句为同位语从句。应将该句区别于：
2）It is said that more middle school graduates will be admitted into universities，this is the information ____ has been put forward.
A. what B. that C. when D. as
析：答案为B。that has been put forward为information的修饰性定语，且information在从句中作主语，所以该句为定语从句。
例2：She heard a terrible noise,____ brought her heart into her mouth.(MET91)
A. it B. which C. this D. that
析：答案为B。分析语境含义、句子结构和句子成分可知，该句为非限制性定语从句，先行词为a terrible noise，且它在从句中作主语。应将该句区别于：
I can't stand the terrible noise ____ she is crying loudly.
A. it B. which C. this D. that
析：答案为D。she is crying loudly是the terrible noise的.内容，且the terrible noise不在从句中作成分，所以该句为同位语从句。
巩固性练习：
1. The fact ____ she works hard is well known to us all.
A. that B. what C. why D. which
2. The fact ____ he was successful proves his ability.
A. hat B. what C. which D. why
3. The news ____ he was kidnapped surprised us greatly.
A. what B. that C. why D. when
4. His suggestion ____ the meeting be delayed was turned down.
A. which B. that C./ D. it
5. I have no idea ____ he will start.
A. when B. that C. what D./
6. I've come from the government with a message ____ the meeting won't be held tomorrow.
A. if B. that C. whether D. which
7. The thought ____ he might fail in the exam worried him.
A. when B. which C. what D. that
8. The order ____ the prisoner be set free arrived too late.
A. which B. whether C. that D. what
9. The nurses are trying their best to reduce the patient's fear ____ he would die of the disease.
A. that B. as C. of which D. which
10. He often asked me the question ____ the work was worth doing.
A. whether B. where C. that D. when
Keys: 1-5 AABBA 6-10 BDCAA
同位语从句和定语从句的三点区别
同位语从句和定语从句很相似,但还是有区别的,区别主要在以下三方面:
1. 从词类上区别
同位语从句前面的名词只能是
idea,fact,news,hope,belief,suggestion,proposal,word,thought,doubt,truth,possibility,promise,order等有一定内涵的名词?而定语从句的先行词可以是名词?代词?主句的一部分或是整个主句?如:
The possibility that the majority of the labour force will work at home is often discussed. (同位语从句)
We are not looking into the question whether he is worth trusting. (同位语从句)
Word came that he had been abroad. (同位语从句)
Our team has won the game, which made us very happy.
我们的队赢了,这让我们很高兴?(定语从句)
The doctor whom you are looking for is in the room.
你找的那位医生在房间里面?(定语从句)
His mother did all she could to help him with his study.他妈妈尽她的最大努力帮助他的学习?(定语从句,代词all作先行词?)
2. 从性质上区别
定语从句是从句对其先行词的修饰或限制,属于形容词性从句的范畴;而同位语从句是从句对前面抽象名词的进一步的说明和解释,属于名词性从句的范畴。如:
The news that our team has won the game was true. 我们队赢了那场比赛的消息是真的?(同位语从句,补充说明news到底是一个什么消息?)
The news that he told me yesterday was true. 昨天他告诉我的那个消息是真的?(定语从句,news在从句中作told的宾语?)
I made a promise that if anyone set me free I would make him very rich. 我许诺如果谁让我自由,我就让他非常富有?(同位语从句,补充说明promise到底是一个什么诺言?)
The mother made a promise that pleased all her children. 妈妈做出了一个令她的孩子们高兴的许诺?(定语从句,promise在从句中作pleased的主语?)
3. 从引导词及其在句子中的成分上区别
有些引导词如how, whether, what可以引导同位语从句,但不能引导定语从句?如:
That question whether we need it has not been considered. 我们是否需要它这个问题还没有考虑?(同位语从句)
I have no idea what has happened to him. 我不知道他发生了什么事?(同位语从句)
引导词that引导定语从句时,在从句中一般作主语或宾语(指物时还可以用which代替),并且作宾语时常常省略?that在同位语从句中仅起连接作用,不充当任何成分,并且不能省略,也不能用which来代替?如:
The order that we should send a few people to help the other groups was received yesterday. 我们应派几个人去帮别的几个小组的命令昨天收到了?(同位语从句,是对order的具体解释,that虽不作成分,但不能省略?)
The order that we received yesterday was that we should send a few people to help the other groups. 我们昨天收到的命令是我们应该派几个人去帮助别的几个小组?(定语从句,是名词order的修饰语,that在从句中作received的宾语,可以省略?)
第1组 五大基本句型
1.主语+不及物动词(短语)
【例句】Birds can fly.鸟会飞。
2.主语+及物动词(短语)+宾语
【例句】Everybody made fun of him.人人都取笑他。
3.主语+连系动词+表语
【例句】These flowers are very beautiful.这些花非常漂亮。
4.主语+及物动词+间接宾语+直接宾语
【例句】My parents bought me a nice Christmas present.父母给我买了一件精美的圣诞礼物。
5.主语+及物动词+宾语+宾语补足语
【例句】They painted the door red.他们把门漆成了红色。
第2组 It句型
1.It+be/get+形容词/名词/介词短语
【用法】it用作非人称代词时，常表示天气、日期、时间、距离、温度等。
【例句】It gets colder and colder.天气变得越来越冷。
2.It+be+被强调部分+that从句
【用法】构成强调句，强调句子的主语、宾语、状语。被强调部分指人时，that可以换成who,其他情况一律用that。
【例句】It was our manager that/who met me at the airport yesterday.昨天是我们的经理去机场接我的。
3.It+be+形容词(+for sb.)+to do sth.
【例句】It is necessary to increase your vocabulary in studying English.在学习英语中增加你的词汇量是必要的。
4.It+be+形容词(+of sb.)+to do sth.
【例句】It is clever of him to work out such a difficult problem.他把这么难的问题给解决了，他真聪明。
5.It+be+形容词+that从句
【例句】It is quite clear that the ear of the elephant is like a huge fan.很显然，大象的耳朵像一把大扇子。
6.It+be+过去分词+that从句
【例句】It is often said that human beings are naturally equipped to speak.据说，人类天生具有会话能力。
7.It+be+名词+不定式/that从句
【用法】it作形式主语，后面的不定式或that从句是句子的真正主语。
【例句】In fact, it is a hard job for the police to keep order in an important football match.实际上，对警察来说，在一场重大的足球赛中维持秩序是一项艰难的工作。
8.It+is/has been+时间段+since...
【例句】It is three years since I came here.我来这儿已经3年了。
9.It+be+(high) time...
【例句】It is time for lunch.该吃午饭了。
第3组 疑问代词
1.What+be+主语?
【用法】用于询问职业。
【例句】What is your elder sister?你姐姐是干什么的?
2.What+be+主语+like?
【用法】用于询问某人/物是什么样的或怎么样。
【例句】One of the twins is very active. What is the other like?这对双胞胎中的一个很活跃。另一个怎么样?
3.What+do/does+主语+look like?
【用法】用于询问外貌或长相。
【例句】What does Clark look like?克拉克长什么样?
4.What do you think of...? 关于……你有什么看法?
【用法】用来询问对某人或某事物的看法。
【例句】What do you think of our new English teacher?你认为我们的新英语老师怎么样?
第4组 不定代词
1.one..., the other...
(两者中的)一个……，另一个……
【例句】He has two sons. One is a doctor and the other is a soldier.他有两个儿子。一个是医生，另一个是军人。
2.some..., others...(不确定范围中的)
一些……，另一些……
【例句】Some boys are playing football, and others are playing basketball.一些男孩子在踢足球，另外一些在打篮球。
3.none (+of+复数可数名词或不可数名词)
【用法】none接指人或物的可数名词或不可数名词，后面可以跟of结构;no one只能接指人的可数名词，后面不能跟of结构。
【例句】None of the money was missing.钱一点儿也没丢。
第5组 年龄
1.at (the age of)+基数词在……岁时
【例句】He was struck down by cancer at (the age of) thirty.他30岁时死于癌症。
2.in one’s+整十数的复数 在某人几十多岁时
【例句】My mother became a professor in her thirties.我妈妈三十多岁时就成了一名教授。
3.基数词+years old ……岁
【例句】He is eighteen years old, when he starts to live on his own.他18岁了，是开始独立生活的年龄了。
第6组 倍数
1.倍数+as+形容词/副词原级+as... ……是……的……倍
【例句】Ten years ago the population of our village was twice as large as that of theirs.十年前我们村的人口是他们村人口的两倍。
第7组 形容词的原级、比较级、最高级
1.as+形容词原级+as...
……和……一样……
【例句】Mary's spoken English is as good as mine.玛丽的口语和我的一样好。
2.not as/so+形容词原级+as...
……不像……一样……
【例句】She is not as/so happy as she pretends.她并不像她假装得那么高兴。
3.形容词比较级(+名词)+than...
……比……更……
【例句】Lesson Four is more difficult than Lesson Three.第四课比第三课难。
4.no+形容词比较级+than...
……和……一样都不……
【例句】I am no taller than you.我和你一样都不高。
5.形容词比较级+and+形容词比较级...
越来越……
【例句】The computer is cheaper and cheaper.电脑越来越便宜了。
6.be senior/junior/superior/inferior to...
……比……大/小/好/差
【例句】I am five years senior to Jane.我比简大五岁。
7.the+(序数词+)形容词最高级(+名词)(+比较范围) (……中)最/第几……的(……)
【例句】The Yellow River is the second longest river in China.黄河是中国的第二长河。
第8组 副词的原级、比较级、最高级
1.as+副词原级+as...
……和……一样……
【例句】John works as hard as his elder brother.约翰和他哥哥一样工作努力。
2.not...+as/so+副词原级+as...
……不如……
【例句】It doesn't rain as/so often here as it does in my country.这里不如我们国家下雨频繁。
3.副词比较级+than...
……比……更……
【例句】Usually the paperback book is more widely accepted than the hardcover one.通常来说，平装书要比精装书更容易被接受。
4.not+副词比较级+than...
前者不比后者更……(侧重后者)
【例句】I run not faster than my deskmate.我不比我同桌跑得快。
5.副词比较级+and+副词比较级...
越来越……
【例句】He ran faster and faster on the last lap.他在最后一圈时跑得越来越快。
6.like...better (than...)
和……比起来，更喜欢……
【例句】I like movies better than TV plays.比起电视剧，我更喜欢电影。
第9组 副词的常用句型
1.too...to... 太……而不能……
【用法】to后用动词原形，表示结果。
【例句】The girl is too young to dress herself.这个女孩太小，不能自己穿衣服。
2.enough to... ……足以……
【用法】to后用动词原形，表示结果。
【例句】Would you be good enough to take my bag upstairs for me?你能否好心帮我把包拿到楼上?
3.so+主语+be/助动词/情态动词 ……确实如此
【例句】—It was very cold yesterday.昨天很冷。
—So it was.确实很冷。
第10组 情态动词常用句型
1.would rather do...than do...
宁愿……，也不……
【例句】She would rather fail than cheat in the examination.她宁愿
2.cannot but do... 只好做……
【用法】but后的不定式要省略to。
【例句】We cannot but wait until Jane comes.我们只好等到简来。
3.cannot/can never...too...
再……也不为过，越……越好
【例句】You cannot be too careful to cross the road.过马路时再怎么小心都不为过。
4.主语+used to/would+do... 过去常常
【例句】I would go swimming in this river when I was young.我小时候常在这条河里游泳。
5.had better (not) do... 最好(不)做……
【例句】You had better not wait for them.你最好不要等他们。
6.must have done... 一定/准是做过……
【用法】表示对过去情况的推测，只用于肯定句中。
【例句】She knows the story very well. She must have read the book.她对这个故事很熟悉。她一定读过这本书。
第11组 不定式
1.(not)in order (not)so as (not) +to do... 不定式作目的状语
【用法】to do, in order to do作目的状语可以位于句首，但so as to do不可以。
【例句】In order not to be late, she cut across the fields.为了不迟到，她抄近路穿过了田野。
2.so+形容词/副词+as
too+形容词/副词
形容词/副词+enough+to do... 不定式作结果状语
【例句】How could you be so stupid as to believe him?你怎么这么笨，竟然相信他的话?
第12组 动名词
1.stop doing...stop to do停止原有的动作...停下来去做另一件事
【例句】Many people stop doing exercise when they eat less.很多人吃得少的时候就不锻炼了。
2.forget/remember doing...忘记/记得做过
forget/remember to do... 忘记/记得要做
【例句】He forgot telling her about the final exam.他不记得已告诉过她关于期末考试的事了。
3.nmean doing...mean to do...意味着做……打算做……
【例句】My new job will mean travelling all over the world.我的新工作需要在世界各地到处跑。
4.regret doing...regret to do...后悔以前曾做过……很遗憾要做……
【例句】—Robert is indeed a wise man.罗伯特确实是个很聪明的人。
5.try doing...try to do...试着做……努力去做……
【例句】She tried living alone, but she didn’t like it and moved back home.她尝试着一个人生活，但并不喜欢这样，于是又搬回家了。
第13组 感叹句
1.How+形容词/副词(+主语+谓语)!How+主语+谓语!
【例句】Look! How excited the boys are!看!那些男孩多么兴奋!
2.What(+a/an)+形容词+名词+(主语+谓语)!
【用法】单数可数名词前有形容词修饰时，用what和how引导感叹句均可，但要注意冠词与形容词的位置。中心词为可数名词复数或不可数名词,只能用what引导感叹句。
【例句】What a wonderful plan you have made!/How wonderful a plan you have made!你制订的计划真棒!
第14组 反意疑问句
1.(陈述部分)肯定，(附加问句)否定?(陈述部分)否定，(附加问句)肯定?
【例句】 He must work hard at physics, mustn’t he?他必须努力学习物理，是吗?
2.No one/Someone...+谓语...，谓语+they?谓语+he?
【用法】陈述部分主语为指人的不定代词，强调整体时，附加问句的主语用they;强调个体时，附加问句的主语用he。
【例句】No one was there that day, was he/were they?那天没有人在那里，是吗?
3.Everything/Anything...+谓语...，谓语+it?
【用法】陈述部分主语是指物的不定代词时，附加问句的主语用it。
【例句】Everything that he said is true, isn’t it?他说的都是真的，是吗?
4.This/That+谓语...，谓语+it?These/Those+谓语...，谓语+they?
【用法】陈述部分的主语是指示代词时，附加问句的主语要用相应的人称代词。
【例句】This means we have failed, doesn’t it?这意味着我们已经失败了，是吗?
5.There be...，谓语+there?
【用法】陈述部分为There be句式时，其反意疑问句的附加问句仍用“...there”。
【例句】There will be an important meeting tomorrow, won't there? 明天有一个重要的会议，是不是?
6.祈使句。will you/won’t you?
【用法】肯定祈使句的反意疑问句，附加问句用will you, 〖JP〗won't you均可;否定祈使句只能用will you。
【例句】Come and play football with us, will you/won't you?过来和我们一起踢足球，好吗?
7.Let's..., shall we?Let us/Let me..., will you?
【例句】Let's have lunch together, shall we?我们一起吃午饭吧，好吗?
第15组 主语从句
1.引导词+主语从句+谓语...
【例句】Whether she will join us does not matter too much.她是否会加入到我们中来并不太重要。
2.It(形式主语)+谓语...+引导词+主语从句
【例句】It is a pity that you missed such a good lecture.你错过了一场这么好的讲座真是可惜。
第16组 宾语从句
1.主句+that引导的宾语从句
【例句】They told us once again that this would never happen.他们再次告诉我们这种事情不会发生。
2.主语+系动词+afraid/sorry/sure/glad/angry等+that引导的宾语从句
【用法】that在宾语从句中没有意义，也不作成分，只起引导词的作用，一般可以省略。
【例句】I'm sure that he will come tomorrow.我确信他明天会来。
3.主句+what/who/whom/whose/which等引导的宾语从句
【用法】what, who, whom, whose, which等连接代词在从句中作主语、宾语、表语或定语等。
【例句】Do you know who/whom he is waiting for at the school gate?你知道他正在学校门口等谁吗?
4.主句+when/where/how/why等引导的宾语从句
【用法】when, where, how, why等在从句中作状语,表示时间、地点、方式、原因等。
【例句】We haven't discussed yet where we are going to place our new furniture.我们还没有讨论应把我们的新家具放在哪里。
5.主句+whether/if引导的宾语从句
【例句】Did he tell you whether/if he would come the next day? 他告诉你他第二天是否来了吗?
6.Whether引导的宾语从句，+主句
【例句】Whether this is true or not， I am not sure.我不确定这是不是真的。
7.主句+whether引导的宾语从句+if条件句
【例句】He asked me whether I would move to New York if I got the job.他问我如果我得到那份工作是否会搬到纽约去。
第17组 表语从句
1.主语+be+引导词+表语从句
【例句】The reason why she called me was that she would not attend the party.她给我打电话的原因是她不来参加派对了。
第18组 同位语从句
1.(...+)名词+引导词+同位语从句
【例句】He received the order that he should come back by the noon.他收到命令，中午之前要回来。
第19组 定语从句
1.主句+who/whom引导的定语从句
【用法】who是主格，whom是宾格。通常whom可以用who代替，但直接跟在介词后作宾语时不可用who代替。who/whom作宾语时可以省略。
【例句】Do you know the girl who is standing under the tree?你认识站在树下的那个女孩吗?
2.主句，+which/who/whom/whose/when/where+定语从句
【用法】非限制性定语从句用逗号与主句分开，that不能引导非限制性定语从句,who一般不能替代whom。
【例句】This note was left by Tom, who was here a moment ago.这个便条是汤姆留下的，刚才他还在这里。
第20组 状语从句
1.主句+before/after引导的时间状语从句
【例句】It may be many years before the situation improves.这种状况或许要过很多年才能得到改善。
2.主句+since引导的时间状语从句
【用法】since从句常用一般过去时，谓语是短暂性动词时，表示该动作的开始;谓语是延续性动词时，表示该动作或状态的结束。
【例句】It was three weeks since he was ill.他的病已经好了三周了。
3.主句+because/as/since引导的原因状语从句
【例句】The old man asked Lucy to move to another chair because he wanted to sit next to
his wife.那位老人让露西挪到另外一张椅子上，因为他想跟他的妻子挨着坐。
4.主句+(al)though/as/while/even though/even if引导的让步状语从句
【例句】Although regular exercise is very important, it’s never a good idea to exercise too
close to bedtime.尽管经常锻炼很重要，但在临睡前锻炼绝对不是个好主意。
5.主句+so that/in order that/in case引导的目的状语从句
【例句】I’ll run slowly so that you can catch up with me.为了能让你赶上我，我会慢慢跑。
6.主句+if/unless/as long as引导的条件状语从句
【例句】I shall go tomorrow unless it rains.如果不下雨，我明天去。
7.主句+as soon as/directly/immediately等引导的时间状语从句 一……就……
【例句】Directly our maths teacher came in, everyone was quiet.我们的数学老师一进来，大家就都安静下来了。
第21组 There be句型
1.There (+助动词/情态动词)+be+主语...
【例句】There is a lot of meat on the plate.盘子里有很多肉。
2.There+助动词/情态动词+not+be be+not/no+主语...
【例句】There isn’t a telephone in the room.房间里没有电话。
第22组 倒装句型
1.No/Never/Hardly/Seldom/Little等+be/助动词/情态动词+主语...
【用法】表示否定意义的词置于句首时，句子用部分倒装。
【例句】Little did Rose care about her own safety, though she was in great danger herself.尽管自己处于相当危险的境地，但是罗丝几乎没考虑自己的安全。
2.So...+be/助动词/情态动词+主语...+that...
【用法】在so... that...句式中，so...部分置于句首时，主句用部分倒装。
【例句】So sudden was the attack that the enemy had no time to escape.袭击是如此突然，以至于敌人根本没有时间逃跑。
3.Only+状语+be/助动词/情态动词+主语...
【用法】only强调状语置于句首时，主句用部分倒装。
【例句】Only if you eat the correct foods will you be able to keep fit and stay healthy.只有合理膳食才会保持身体健康。
4.Not until...+be/助动词/情态动词+主语...
【用法】时间状语not until...置于句首时，主句用部分倒装。
【例句】Not until the motorbike looked almost new did he stop repairing and cleaning it.直到把摩托车修理、擦洗得几乎跟新的一样他才作罢。
5.Not only...+be/助动词/情态动词+主语...but also...
【用法】not only...置于句首时，其所在的分句用部分倒装，其中also有时可以省略。
【例句】Not only does he do well in his lessons, but he often helps others with their lessons.他不但自己学习好，还经常帮助别人学习。
6.Hardly had+主语...+when...No sooner had+主语...+than....
【用法】hardly, no sooner 置于句首时，hardly, no sooner所在的.句子用部分倒装。
【例句】Hardly had he uttered the words when she began laughing. 他刚一开口说话，她就笑了。
第23组 虚拟语气在状语从句中的用法
1.If...did/were...， 主语+would/should/could/might do...
【用法】表示与现在事实相反的假设。从句用一般过去时，主句谓语动词用“would/should/could/might+动词原形”。
【例句】If I were eleven years younger, I would dance as well as them.如果我年轻11岁，我会跟他们跳得一样好。
2.If...had done...，主语+would/should/could/might have done...
【用法】表示与过去事实相反的假设。从句用过去完成时，主句谓语动词用“would/should/could/might+have+过去分词”。
【例句】If we had taken the other road, we might have arrived here in time for the meeting.如果我们走了另一条路的话，或许就能及时赶到这里开会了。
3.If...did/were to do/should do...，主语+would/should/could/might do...
【用法】表示与将来事实相反的假设。从句谓语动词用过去式、“should+动词原形”或“were to+动词原形”，主句谓语动词用“would/should/could/might+动词原形”。
【例句】If it were fine tomorrow, I would go shopping.如果明天天气好，我就去购物。
4.If...had done...， 主语+would do...
If...should do...， 主语+would have done...
【例句】If he had set out earlier, he would be home now.如果他早点出发的话，他现在就已经到家了。
5.Should/Were/Had+(从句)主语+谓语，主句
【用法】if引导的虚拟条件句的谓语动词中含有should, were, had时，可将if省略，而将should, were, had提前，构成倒装。
【例句】Should it happen(=If it should happen), what would you do?如果真发生了这样的事，你怎么办?
6.With/Without/But for+名词，主语+虚拟语气形式的谓语...
【用法】句子的虚拟条件是通过词或短语如with， without， otherwise, but for等来表示的。
【例 句】But for the help of my English teacher, I would not have won the first prize in the English Writing Competition.如果没有英语老师的帮助，我不可能在英语写作比赛中获得一等奖。
7.主句+as if+(从句)主语+did/had done...
【用法】as if引导的从句常用虚拟语气，用一般过去时表示与现在事实相反的情况;用过去完成时表示与过去事实相反的情况。
【例句】She acted as if she had been the hostess yesterday.她昨天表现得就好像她是女主人似的。
第24组 虚拟语气在名词性从句中的用法
1.wish (that)+主语+did/had done/would do...
【用法】wish后的宾语从句用一般过去时表示与现在事实相反;用过去完成时表示与过去事实相反;用过去将来时表示与将来事实相反。
【例句】I wish it were autumn in Beijing all the year around.我希望北京全年都是秋天。
2.suggest/recommend/insist等+(that)+主语+(should) do...
【例 句】Teachers recommend parents not allow their children under 12 to ride bicycles to school for safety.为了安全，老师建议家长们不要让未满12岁的孩子骑自行车来上学。
3.would rather+主语+did/had done...
【用法】would rather后的从句用一般过去时表示与现在或将来事实相反，用过去完成时表示与过去事实相反。
【例句】George is going to talk about the geography of his country, but I?d rather he focused more on its culture.乔治打算谈谈他们国家的地理，但是我却愿意他多谈一下他们的文化。
4.It is+形容词/名词/过去分词+that+主语+(should) do...
【例句】It is strange that the girl (should) be so rude.那个女孩那么无礼，这真奇怪。
5.suggestion/advice/demand等+that+主语(+should) do...
【用法】在表示“建议”、“命令”、“要求”等的名词后的表语从句和同位语从句中用虚拟语气。
【例句】My suggestion is that we (should) get started soon.我的建议是我们应该尽快出发。
句子的组成部分，包括主语、谓语、宾语、定语、状语、表语、补语、同位语和独立成分9种。
主语是句子叙述的主体，可由名词、代词、数词、名词化的形容词、不定式、动名词和主语从句等来承担。
谓语说明主语所发出的动作或具有的特征和状态。谓语由动词来承担。
宾语是动作的对象或承受者，常位于及物动词或介词后面。宾语可由名词、代词、数词、名词化的形容词、不定式、动名词、宾语从句等来担任。
除少数句子（如祈使句和感叹句等）外，一句话必须同时具有主语和谓语所表达的意思才能完整。主语是针对谓语而言的，是一句话的主题，谓语用来说明主语的情况，为主语提供信息。例如：They are working。主语是they（他们），那么他们在做什么呢？看来没有谓语are working 是不行的。在正常情况下，英语的主语和谓语的位置与汉语一致，也就是说主语在前，谓语紧跟其后。
定语用于描述名词，代词，短语或从句的性质，特征范围等情况的词叫做定语，定语可以由名词，形容词和起名词和形容词作用的词，短语担任。如果定语是单个词，定语放在被修饰词的`前面，如果是词组，定语放在被修饰词的后面。
状语说明事情发生的时间，地点，原因，目的，结果方式，条件或伴随情况，程度等情况的词叫状语。状语一般由副词、介词短语、分词和分词短语、不定式或相当于副词的词或短语来担当。其位置一般放在句末，但也可放在句首或句中，修饰动词、形容词、副词等。
补语的作用对象是主语和宾语，具有鲜明的定语性描写或限制性功能，在句法上是不可或缺的。补语是起补充说明作用的成份。最常见的是宾语补足语。名词、动名词、形容词、副词、不定式、现在分词、过去分词都可以在句子中作宾补。
表语是用来说明主语的性质，身份，特征和状态。表语须和系动词一起构成句子的复合谓语。表语一般放在系动词之后。表语可以由名词，形容词或起名词和形容词作用的词和短语担任。
同位语当两个指同一事物的句子成分放在同等位置时，一个句子成分可被用来说明或解释另一个句子成分，前者就叫做后者的同位语。这两个句子成分多由名词（代词）担任，同位语通常皆放在其说明的名词（代词）之后。同位语和补语的区别在于：补语不能缺少，同位语可以缺少。
独立成分，当一个词、短语或从句用在句子里面，与句子的其他成分只有意义上的联系而没有语法关系时，它就称为独立成分。常见的独立成份有呼吁、惊叹语、答语、插入语、介词短语、非谓语动词所构成的短语及形容词、副词所引起的词组等。
