语法专题名词性从句 (2)

1、语法专题：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, why一 主语从句1. 什么是主语从句？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,

2、 when, where, why等词引导。That 在句中无_, 只起_ 作用；连词that不能省略。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；例如连接词例句从属连词_ the gun powder was first invented by the Chinese is known to us all.众所周知，火药最早是中国人发明的。连接代词_ caused the accident is still a mystery.导致这起事故的原因仍然是个谜连接副词_ we can help the twins will be discussed at the meeting.

3、 我们将在会议上讨论如何帮助那对双胞胎。2. 位置主语从句通常位于句首，但有时主语从句放在句首，句子会显得比较笨重，这时把主语从句移到句末，用_ 作形式主语。常用句型有以下几种：（1） It + be + 形容词 + that从句l It is certain that she will do well in her exam. 她肯定会在考试中取得好成绩。（2） It + be + 动词的过去分词 + that从句l It was suggested that the work (should) be done with great care.据建议，做这份工作时应小心翼翼。（3） It +

4、 be + 名词 + that从句，用于该结构的常用名词有：regret, question, no wonder, pity, news, honor, duty等。 * It is a pity that we wont be able to go to the south to spend our summer vacation. 真遗憾，我们不能去南方过暑假。（4）It + 不及物动词 + that/ whether.从句，常用于该结构的动词有：appear，happen(_)，matter（_）,occur(_),seem 等 *It doesnt matter whether sh

5、e will come or not. 她是否会来无关紧要。l It happened that I was out that day. 恰好那天我出去了。【点津】Whether 引导的主语从句既可以放在句首也可以放在句尾，但if 引导的主语从句只能放在句尾，前面需用it 作形式主语。Whether/if 只起到_作用，译成“_”, 在句中不作成分。l _ Mary really heard him is really doubtful.玛丽是否真正听到了他的话真的很可疑。l _ is really doubtful whether/ if Mary really heard him.二 宾语

6、从句1. 宾语从句的三种分类：在句中起宾语作用的从句叫宾语从句。（1） 宾语从句可分三类：动词后的从句，介词后的从句和形容词后的从句是_。（2） 宾语从句语序必须是_.a. The boy believes that he will travel through space to other planets. 这个男孩相信他会穿过太空去别的星球旅游b. None of us knows where these new parts can be bought.我们没人知道在哪里能买到这些零件。c. The new book is about how he succeeded in overcom

7、ing his cancer.这本新书是关于他如何战胜癌症的。d. I am sorry that I have troubled you so long.很抱歉我打扰你这么长时间。2. 宾语从句的时态1） 如果主句是将来时态或现在时态（包括一般现在时，现在进行时，现在完成时），从句的时态可根据实际情况而定。* I know he lived here four years ago.我知道他四年前住在这里2） 如果主句是过去范畴内的时态（包括一般时态，过去进行时），那么从句中一定要过去范畴内的某种时态（包括一般过去时，过去进行时，过去将来时，过去完成时）* He admitted he had

8、 given away the secret.他承认自己曾经泄露过这个秘密。3） 如果宾语从句表示的是客观事实或真理时，即使主句是过去时，从句也用一般现在时。The teacher said that the moon goes around the earth yesterday.老师昨天说月亮绕着地球转。【点津】当宾语从句的引导词是who, which, what, when, where, how, why等疑问词与do you think/ believe/ suppose/ imagine 连用时，经常将这类引导词置于句首。l Who do you think the public

9、might choose as their favorite singer this year?你认为今年公众会选谁为他们最喜欢的歌手？三 表语从句1. 在句中作表语的从句叫表语从句。常用的连接词与主语从句和宾语从句的连接词相同，用法也一样。还可以用as if/ as though, because来引导。连接词 例句从属连词His suggestion is _ we should stay calm.他的建议是，我们应该保持冷静。连接代词That is _ I want to tell you.那就是我想要对你说的。连接副词The problem is _ we can get the t

10、hings we need.问题是我们怎样能得到我们需要的东西as if/ thoughIt looks _ a storm is on the way.看样子一场暴风雨即将来临。2. 如果主句的主语是 advice, suggestion, order, request, requirement 等名词时，表语从句的谓语要用“_”His suggestion is that the wounded _(send) to hospital immediately.四 同位语从句 1. 同位语从句的表现形式 主句中有些名词词义比较抽象，如belief, doubt, fact, hope, id

11、ea, thought 等，他们往往要求用从句来具体说明这一名词的实际内容或对该名词作进一步解释。这种从句成为同位语从句，其连接词与其他从句一样连接词例句thatThe hope _ he may recover is not gone yet.他可能康复的希望还没有破灭whetherThe question _ we need more time to do the work hasnt been discussed. 我们是否需要更多的时间去做这项工作的问题还没有被讨论。whenI have no idea _ he will be back. 我不知道他何时回来。2. 同位语从句中的虚拟

12、语气order, advice, request, suggestion, proposal 等表示建议、命令、要求的名词后的同位语从句要用虚拟语气。 l We followed his advice that we should ask our teacher for help.我们接受了他的建议：我们应该请求老师的帮助。【易混清单】1. that引导同位语从句& 定语从句连词 连词that引导同位语从句时，应放在某些抽象名词后，如：news, word(消息)， idea, fact, hope, desire, thought 等，对前面的名词起补充说明的作用，连词that只引导

13、同位语从句的作用，在从句中不担任任何成分，因此that引导同位语从句时完整的，不缺任何成分 关系代词that 引导定语从句时，关系代词that一方面起引导 定语从句的作用，另一方面，that在定语从句中担任_、_、_成分。因此，that 引导的定语从句时残缺的。The news that our football team won the match was encouraging. (_从句)The news that we heard in the radio was not true. (_从句) 2. whether & if 表语从句和同位语从句只能用whether引导不能用

14、if; 当主语从句放在句首时，也只能用whether引导不用if;当it 作形式主语，主语从句放在句末时用whether或if 引导均可；discuss后必须用whether引导的宾语从句【例题】 是否开会仍是个问题 _ the meeting will be given is still a problem. = The problem is whether the meeting will be given. = I have no idea _ the meeting will be given. It is doubtful _ he will come here. 他是否要来还令人怀

15、疑3. What & That1) The villagers have already known _ we will do is to rebuild thebridge.2) When the news came _ the war broke out, he decided to serve in the army.3) _ Barbara Jones offers to her fans is honesty and happiness.4) His writing is so confusing that its difficult to make out _ it is

16、he is trying to express.5) _ was most important to her, she told me, was her family6) It never occurred to me _ you could succeed in persuading him to change his mind.7) It is uncertain _ side effect the medicine will bring about, although about two thousand patients have taken it.8) One reason for

17、her preference for city life is _ she can have easy access to places like shops and restaurants.名词性从句 习题I 用连接词填空1. It depends in the climate _ they are going on a picnic this weekend.2. It is important _ he will come here, by ship or by plane.3. She explained the reason _ she was late.4. _ do you th

18、ink is going on outside the classroom?5. China is no longer _ she used to be.6. What the doctors doubt is _ my mother will become well again.7. The truth _ light travels much faster than sound is known to all.8. I have no idea _ we should go on our holiday this summer.9. We havent discussed yet _ we

19、 are going to place our new furniture.10. Before the sales start, I make a list of _ my kids will need for the coming season.11. As a mew graduate, he doesnt know _ it takes to start a business here.12. It is not immediately clear _ the financial crisis will soon be over.13. It has been proved _ eating vegetables in childhood helps to protect you against serious illnesses in later life.14. It doesnt matter _ you pay by cash or credit card in this store.15. It is by no means clear _ the president can do to end the strike.16. It doesnt matter _ you turn right or left at the crossi