1、主语从句一定义：在复合句中，作主语的句子称为主语从句，通常位于谓语动词之前。如：Who will win the match is still unknown.谁会赢得这场比赛，目前还不清楚。二连接词引导主语从句的关联词有从属连词：that、whether、if；关系代词：who,what,which,whom,whose,whatever,whoever,whomever,whichever；关系副词：when,where,how,why,however,whenever,wherever 等从属连词 that，whether 引导的主语从句：引导主语从句，它们在从句中不担任成分，不能省略
2、如：Whether she will come or notWhether she will come or not is still a question.她是否会来仍是一个问题。That they will goThat they will go is certain.他们去是肯定的。注意：whether，if 的区别：（1）whether 引导主语从句可以放句首，也可以放句尾，表示“是否”，不可省略。（2）If 引导的主语从句只能放在句尾，前面要用 it 作形式主语。如：Whether she will come or not is uncertain.她会不会来还不确定。It rema
3、ins to be seen if they can be good parents.他们是否能成为一对合格的父母还有待观察。随堂练习：用 whether,if 或 that 填空1.the meeting will be put off hasnt been decided yet.2.It remains unknown we will go for an outing tomorrow.3.the earth is round is true.4.you missed such an interesting film is a pity.5.shes coming or not does
4、nt matter too much.由关系代词引导的主语从句：who,what,which,whom,whose,whatever,whoever,whomever,whichever 等，引导主语从句时，它们分别在从句中担任主语、宾语或定语，不能省略。如：Whoever leaves the room lastWhoever leaves the room last ought to turn off the lights.无论谁最后离开房间，都应该关灯。注意：no matter who 和 whoever 的区别：1.no matter who 通常只能引导状语从句，而不能引导名词性从句
5、。2.whoever 既可引导名词性从句也可引导状语从句关系副词引导的主语从句：when,where,why,how,however,whenever,wherever 等引导主语从句时，它们在从句中担任状语，不能省略。如：Why he didnt come hereWhy he didnt come here is not clear to anyone.他为什么没来谁也不清楚。How a telephone worksHow a telephone works is a question which not everyone can answer.电话是怎样工作的，这个问题并不是每个人都能
6、回答。Where she has goneWhere she has gone is not known yet.她去了哪儿，还不知道。When they will start When they will start has not been decided yet.他们何时动身还未定下来。随堂练习1.you dont like him is none of my business.A.What B.Who C.That D.Whether2.well go camping tomorrow depends on the weather.A.If B.Whether C.That D.Whe
7、re3.is going to do the job will be decided by the manager.A.That B.Why C.How D.Who4.well finish translating the book depends on the time.A.When B.Why C.What D.That5.he wont go there is clear to all of us.A.How B.What C.Why D.This三有时为了避免头重脚轻，常用 it 作形式主语，真正的主语放后面。it 作形式主语的常用句型It+be+形容词（clear/unfair 等）
8、+that.如：Its strange that he didnt come yesterdaythat he didnt come yesterday.他昨天没来是很奇怪的。It+be+名词词组（a fact/a pity/a shame 等）+that.如：It is a question that It is a question that who will hold the meeting.谁来主持会议是个问题。It+be+过去分词（announced/believed/expected 等）+that.如：It is said that there was a terrible pl
9、ane crash this morningthat there was a terrible plane crash this morning.据说今天早上有一起可怕的飞机坠毁事故。It+seems/appears/happens 等+that.如：It seems that he is a good guy.他似乎是个好人注意：在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should)+do”如：It is a pity that you(should)have to leave.真遗憾你非走不可。随堂练习：翻译句子1.吸烟危害健康，这是事实。2.中国
10、人口众多是一件极大的好事。3.据说 Jack 篮球打得很棒。4.对她来参加聚会来说很重要。5.他们似乎已经离开了北京。四主语从句不可位于句首的四种情况。（1）含主语从句的复合句是疑问句、感叹句时，主语从句不可提前，用引导词 it 作形式主语。如：Is it really true that he has gone abroadthat he has gone abroad?他真的出国了吗？How surprising it was that he failed in the examthat he failed in the exam!真令人惊奇，他考试没有及格！（2）It is said,r
11、eported,结构中的主语从句不可提前。如：Its said that the play is very interestingthat the play is very interesting.据说戏剧很有趣。Its reported that the highway will be opened to traffic next week.that the highway will be opened to traffic next week.据报道，高速路下周通车。（3）It happens,occurs结构中的主语从句不可提前。如：It occurred to her that she
12、 had forgotten to lock the door.that she had forgotten to lock the door.她突然想起忘了锁门。It happened that I met him in the streetthat I met him in the street.我恰巧在大街上遇到了他。（4）It doesnt matter how,whether or not结构中的主语从句不可提前。如：It doesnt matter whether he likes it or not.whether he likes it or not.他喜欢与否无关紧要。五it
13、 作形式主语与 it 引导强调句的比较。强调句：去掉 it is.that 部分，句子意思仍然完整如：It is certain that that she will succeed.她会成功是肯定的。（主语从句）It is in New York that that I met him.是在纽约我见到了他。（强调句）随堂练习：用适当的连接词填空1.It is probable it will rain today.2.you dont like him is none of my business.3.matters most in learning English is enough pr
14、actice.4.breaks the law can never escape from being punished.5.of them will take charge of our company is still being discussed.6.worries us most is that the number of the kids dominated by computers is growing fast.7.one can turn his dream into a reality depends on his talent and the efforts he mak
15、es.8.I believe is that you need to act smartly,instead of following what everyone else is doing.9.It is required in the regulations you shouldnt tell other people the password of your e-mail account.10.It has been proved eating vegetables in childhood helps to protect you against serious illnesses i
16、n later life.主语从句一定义：在复合句中，作主语的句子称为主语从句，通常位于谓语动词之前。如：Who will win the match is still unknown.谁会赢得这场比赛，目前还不清楚。二连接词引导主语从句的关联词有从属连词：that、whether、if；关系代词：who,what,which,whom,whose,whatever,whoever,whomever,whichever；关系副词：when,where,how,why,however,whenever,wherever 等从属连词 that，whether 引导的主语从句：引导主语从句，它们在从
17、句中不担任成分，不能省略 如：Whether she will come or notWhether she will come or not is still a question.她是否会来仍是一个问题。That they will goThat they will go is certain.他们去是肯定的。注意：whether，if 的区别：（1）whether 引导主语从句可以放句首，也可以放句尾，表示“是否”，不可省略。（2）If 引导的主语从句只能放在句尾，前面要用 it 作形式主语。如：Whether she will come or not is uncertain.她会不会
18、来还不确定。It remains to be seen if they can be good parents.他们是否能成为一对合格的父母还有待观察。随堂练习：用 whether,if 或 that 填空1.Whether the meeting will be put off hasnt been decided yet.2.It remains unknown whether/if we will go for an outing tomorrow.3.That the earth is round is true.4.That you missed such an interestin
19、g film is a pity.5.Whether shes coming or not doesnt matter too much.由关系代词引导的主语从句：who,what,which,whom,whose,whatever,whoever,whomever,whichever 等，引导主语从句时，它们分别在从句中担任主语、宾语或定语，不能省略。如：Whoever leaves the room lastWhoever leaves the room last ought to turn off the lights.无论谁最后离开房间，都应该关灯。注意：no matter who 和
20、 whoever 的区别：1.no matter who 通常只能引导状语从句，而不能引导名词性从句。2.whoever 既可引导名词性从句也可引导状语从句关系副词引导的主语从句：when,where,why,how,however,whenever,wherever 等引导主语从句时，它们在从句中担任状语，不能省略。如：Why he didnt come hereWhy he didnt come here is not clear to anyone.他为什么没来谁也不清楚。How a telephone worksHow a telephone works is a question w
21、hich not everyone can answer.电话是怎样工作的，这个问题并不是每个人都能回答。Where she has goneWhere she has gone is not known yet.她去了哪儿，还不知道。When they will start When they will start has not been decided yet.他们何时动身还未定下来。随堂练习C1.you dont like him is none of my business.A.What B.Who C.That D.WhetherB2.well go camping tomorro
22、w depends on the weather.A.If B.Whether C.That D.WhereD3.is going to do the job will be decided by the manager.A.That B.Why C.How D.WhoA4.well finish translating the book depends on the time.A.When B.Why C.What D.ThatC5.he wont go there is clear to all of us.A.How B.What C.Why D.This三有时为了避免头重脚轻，常用 i
23、t 作形式主语，真正的主语放后面。it 作形式主语的常用句型It+be+形容词（clear/unfair 等）+that.如：Its strange that he didnt come yesterdaythat he didnt come yesterday.他昨天没来是很奇怪的。It+be+名词词组（a fact/a pity/a shame 等）+that.如：It is a question that It is a question that who will hold the meeting.谁来主持会议是个问题。It+be+过去分词（announced/believed/exp
24、ected 等）+that.如：It is said that there was a terrible plane crash this morningthat there was a terrible plane crash this morning.据说今天早上有一起可怕的飞机坠毁事故。It+seems/appears/happens 等+that.如：It seems that he is a good guy.他似乎是个好人注意：在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should)+do”如：It is a pity that you(sh
25、ould)have to leave.真遗憾你非走不可。随堂练习：翻译句子1.吸烟危害健康，这是事实。It is a fact that smoking is a danger to health.2.中国人口众多是一件极大的好事。It is a good thing that China has a big population.3.据说 Jack 篮球打得很棒。Its said that Jack plays basketball very well.4.对她来参加聚会来说很重要。It is important for her to come to the party.5.他们似乎已经离开
26、了北京。It seems that they have already left Beijing.四主语从句不可位于句首的四种情况。（1）含主语从句的复合句是疑问句、感叹句时，主语从句不可提前，用引导词 it 作形式主语。如：Is it really true that he has gone abroadthat he has gone abroad?他真的出国了吗？How surprising it was that he failed in the examthat he failed in the exam!真令人惊奇，他考试没有及格！（2）It is said,reported,结构
27、中的主语从句不可提前。如：Its said that the play is very interestingthat the play is very interesting.据说戏剧很有趣。Its reported that the highway will be opened to traffic next week.that the highway will be opened to traffic next week.据报道，高速路下周通车。（3）It happens,occurs结构中的主语从句不可提前。如：It occurred to her that she had forgo
28、tten to lock the door.that she had forgotten to lock the door.她突然想起忘了锁门。It happened that I met him in the streetthat I met him in the street.我恰巧在大街上遇到了他。（4）It doesnt matter how,whether or not结构中的主语从句不可提前。如：It doesnt matter whether he likes it or not.whether he likes it or not.他喜欢与否无关紧要。五it 作形式主语与 it
29、 引导强调句的比较。强调句：去掉 it is.that 部分，句子意思仍然完整如：It is certain that that she will succeed.她会成功是肯定的。（主语从句）It is in New York that that I met him.是在纽约我见到了他。（强调句）随堂练习：用适当的连接词填空1.It is probable that it will rain today.2.That you dont like him is none of my business.3.What matters most in learning English is enou
30、gh practice.4.Whoever breaks the law can never escape from being punished.5.Which of them will take charge of our company is still being discussed.6.What worries us most is that the number of the kids dominated by computers is growing fast.7.Whether one can turn his dream into a reality depends on h
31、is talent and the efforts he makes.8.What I believe is that you need to act smartly,instead of following what everyone else is doing.9.It is required in the regulations that you shouldnt tell other people the password of your e-mail account.10.It has been proved that eating vegetables in childhood helps to protect you against serious illnesses in later life.
