名词性从句主语从句

1、主语从句导入：观察并指出句子成分A tree has fallen across the road.You are a student.To find your way can be a problem.Smoking is bad for you.一 概念： 主语：主语是指句子谈论的主题，说明的人或事物。也就是句中动作、行为、性质和状态的主体，一般位于句首主语从句：在句中充当主语的从句二基本结构关系词 简单句 谓语动词 宾语同位语 That he finished writing the composition in such a short time surprised us all.他在

2、很短的时间内写完作文让我们都很惊讶三关系词(引导词)1从属连词： that whetherthat 引导主语从句只起引导作用，本身无实际意义，在主语从句中不充当任何成分， 但不能省略。That she left him cut him to the heart.That he will come is certain.注意：有时为了使句子结构平衡 , 避免“头重脚轻” , 常用 it 作形式主语 , 而把从句 放在后面。 E.gThat she has made such a mistake is a pity.It is a pity that she has made such a mis

3、take. 这样就构成了下面一些常用句型 :1) It is + adj. +从句It is necessary that 有必要It is important that.重要的是It is obvious that 很明显2) It + 不及物动词 +从句It seems/appears that.似乎It happened that.碰巧It occurred to me that 我突然想起3) It + be + 过去分词 +从句It is said that.据说众所周知 据报道 据信 ;人们相信 有人建议 必须指出 已证明.hat 是常识 . 令人惊奇的是 事实是It is kno

4、wn to all that.It is reported that.It is believed that.It is suggested that.It must be pointed out that. It has been proved that.4) It is + n. +从句It is common knowledge tIt is a surprise that It is a fact that由 whether 及其他连词引导的主语从句放在句首，句后都可。 Whether it will please them is hard to say.It is hard to s

5、ay whether it will please them.2. 连接代词： who whoever whom whose what whatever which whichever What seems easy to some people seems difficult to others.Which side will win is not clear.注意：what 与 that 在引导主语从句时的区别what 引导主语从句时在从句中充当句子成分 , 如主语、宾语、表语 , that 则不充当任何成分无意义。例如：What you said yesterday is right.

6、That she is still alive is a consolation3. 连接副词： when where how why 等 Why he did it remains a mystery.When they will start is not known yet.How he became a great scientist is known to us all.It s certain. Well be late.Is he coming or not? We dont knowWhat does he want to tell us? We dont knowWhen wi

7、ll you come back? It doesn t matter.四主语从句需注意的问题1 一个句子作主语时，主句的谓语动词应为单数。Eg Whether he will come depends on the weather.2 what 引导的句子作主语时，谓语动词的数由句子的内容决定（即由表语决定 ） 。What I want is money.What we need are good booksWhat he said is reasonable.What we will do hasnt been decided.3 Where he was born and where h

8、e lives now are not clear.Where and when he was born remains a secret.两个或两个以上的主从联合做主语，主句谓语动词应为复数。 两个或两个以上的连词引导一个从句，主句谓语动词应为单数。（ 不能换成 if）可以与 if 进行替换 ）4 W hether he will come isn t clear.It isnt clear whether /if he will come. （ if 不能置于句首）5. It 作形式主语和 it 引导强调句的比较It is+ 名词/ 形容词/ 过去分词+主语从句常用 it 作形式主语，一般

9、常用句型为： 主语从句例如：It is still a question whether she will come or not.It is strange that you should like him.It is still unknown which team will win the match. 另外，还有一些比较多见的结构： It turned out that;It has been proved thatIt happened/occurred thatIt is well- known that 等等而 强调句 则不同，它的结构是： It+be+ 被强调部分 +that+

10、 从句强调主语：It is the times that produce their heroes.时势造英雄强调宾语： It is English that Prof.Lin teaches us.强调状语：It was in shanghai that I saw the film. 判断是否是强调句有一个方法，就是将 that 以后的“句子的其余部分”拿出来单独 看，看有没有缺成分，缺的是什么成分，再把 谓语动词后面 that 前面的那部分，带到你认 为缺成分的地方，如果放进去是一句完整的句子了，那就说明是强调句。6. 用于 It is important / natural / nec

11、essary / impossible that.句型中 , 主语从句应使用虚拟语气 , 谓语动词用 “should + 动词原形 ”的形式 , should 有时有感 情色彩。It be suggested/ advised/ ordered/requested that sb （should） do sth主语从句练习题一翻译1（ 谁将去接他 ） is not decided.2（ 哪个班极会赢得这场足球赛 ） is not clear .3 （ 他能否买到飞机票 ） doesnt mattermuch.4（ 我们如何去那里 ） is a question.5（ 你刚才告诉我的 ）w as

12、 really a surprise.6（ 他什么时候出国 ） is being discussed7（ 他为什么哭 ） is not clear.8It is clear（ 他是一个乞丐 ）.9（ 你要请谁 ） is not important.10（ 我们将在哪里举行篮球赛 ） is not clear.二找出下列句子中的主语从句及其引导词，并指出引导词是否充当成分，充当什么成分。1. That we shall be late is certain.2. That the driver could not control his car was obvious.3. It is cert

13、ain that we shall be late.4. It was obvious that the driver could not control his car.5. Is it possible that they will come tomorrow？6. It is clear that he was telling the truth.7. It s probable that we ll be a little late.8. What caused the accident is a complete mystery.9. It worried her a bit tha

14、t her hair was turning grey.10. It shocked me that Peter didnt tell anybody where he was.11. Who was responsible for the accident is not yet clear.12. It s a pity that you cant go with us.13. What he did is not yet known.14. It is said that he has been there many times.15. It is not yet clear who wa

15、s responsible for the accident.16. When they will have the sports meet is still a question.17. It seems that he has lost something.18. What he said at the meeting encouraged everyone.19. What caused the accident was a broken bottle.20. It remains a problem whether it is true.21. Whoever breaks the l

16、aw is sure to be punished.22. What she looks like doesn t matter.23. How this happened is not clear to anyone.24. Whoever comes is welcome.t c lear.25. Whether hell come here isn三用适当的引导词填空。1. It is likely he is the winner of this game.很可能他是这场游戏的胜利者。2. she bought so many dictionaries is not clear.= I

17、t is not clear she bought so many dictionaries.不清楚她为什么买这么多字典。3. he was admitted into Beijing University made his teachers and parentshappy.他考上了北大，这让他的老师和父母很高兴。4. It s a pity you can t attend my birthday party.很可惜你不能参加我的生日聚会。5. we will build a new high school hasn t been decided.我们是否要建新高中还没决定呢。6. bre

18、aks the law should be punished.不管谁违法都应该受到惩罚。7. It is necessary the problem (should) be solved at once.很有必要立刻解决这个问题。8. he was born is unknown.他生于何时还不知道。9 It is possible he has stolen the car.很可能他偷了小车。10. has broken the glass is unknown.谁打破了玻璃现在还不知道。11. he wants is all here.他所要的东西都在这里。12. he worked it

19、 out is still a secret.他是如何把它做出来的还是一个秘密13. they makes in this factory are TV sets.他们在工厂里所做的东西就是电视机。14. they would support us was a problem.他们是否会支持我们还是一个问题。15. you want is yours.你要哪个哪个就是你的。16. we need is money.我们需要的是钱。17. we arrive doesn t matter.什么时候到没有关系。18. it was done was a mystery.这是怎样做的是一个谜。19

20、this happended is not clear to anyone.这件事怎样发生的，谁也不清楚。20. I spend my summer is no business of yours.我在哪里过暑假不关你的事。D.it6. _ shehad forgottento takeA.Thatoccurred toherher notebook.B. She occurred that三选择题1. _as muchas one-fifthof alltimber harvested is notused.A.TheestimateB.TheestimatedC.Theyare estim

21、atedD. Itisestimated that2.some mammals cameto live inthesea is not known.A.WhichB.SinceC. AlthoughD.How3.we haveachievedis attributedtothe guidance ofourparentsA.WhoeverB.WhateverC. HoweverD.That4.wealthydoes notnecessarilymeanthat a man is greedy.A.For thereason that he isB. Just becauseheisC. The

22、 reason of beingD.That he is5. Although _ happened in this developedcountrysoundslike science fiction, itcould occur elsewhere in theworld.A. whichB. whatC.howC. To her thatoccurredD.It occurred to herthat7.I am sure that shesaid is wrong.A. whichB.allC.thisD. what8.We lost our wayin theforest, and

23、madematters worse wasthat it was gettingdark.A. thatB. whichC.itD. what9. or not isstill uncertain.A. Hes comingB. If he is comingCThatcomingD. Whether he s coming10. Its _ hellbeable tocome.A.doubtwhetherB.doubtfulC. doubt itD. doubtfulwhether11. _ he isat work inthe heart of the big cityorat home inthe quietsuburb, Dick s life istiedto machines.A.WhetherB.TillC.IfD. Unless12. _ he saw bothsurprisedandfrightenedhim.A.ThatB.WhenC. WhatD.Which13. _ iswarmsunshine.A.What doweallneed.B. Whatall we need CWhatwe needD.What we all