名词性从句语法解释.doc

名词性从句：主语从句、宾语从句、表语从句和同位语从句在句中的作用相当于一个名词，所以把它们统称为名词性从句一、宾语从句注意一：引导词的选择：1). Youll have to decide_ car well use, yours or mine.2). Youll have to decide_ car well use, the old one or the new one.3). Youll have to decide_ well use the new car for.4). Youll have to decide_ well use the new car. A. whichB. whatC. whoseD. whether提醒1：check/make sure 不用if/whether 引导从句，而用that:Check that everything is in order, please. Make sure that the door is locked before you leave the lab.提醒2：doubt：肯定：_ 否定/疑问：_I doubt _ she is liked.I dont doubt _she is liked.Do you doubt _she is liked?提醒3： I am sure _; I am not sure _I am not sure whether/if the news is true.I am sure that the news is true.注意二：从句的谓语动词形式：当主句的谓语动词为过去时态时，从句的动词要用相应的过去时态（适用所有从句） He said he would come if he had time.例外：1. 当从句为客观真理或普遍事实时， 用一般现在时：The teacher said that the earth turn around the sun. 2. 当主句谓语动词为一坚持、二命令、三建议、四要求等动词时， 从句常用should+v原 He demanded that they should be there on time.注意三：从句的语序：所有从句都用陈述句语序：I dont know where he has gone.注意四：混合型的宾语从句：1. 否定的转移：当主句的谓语动词为think, suppose, expect, believe, imagine等时，其后的宾语从句为否定句时，常将否定词not 从从句中转移到主句中，构成否定转移： We dont think there is anything of interest in your picture.2. 插入语：wh- +do you think/believe/suppose/suggest? What do you suppose they need? Where do you think the boy has gone?注意五：in that : 在于，因为：引导宾语从句 Human beings are different from animals in that they can use languages as a tool to communicate.注意六：形式宾语的运用：1. S+V+it+adj/n+to do/doing/从句 He made it clear that he would leave office soon. Dont take it for granted that your parents should do everything for you.2. 固定：like, dislike, hate, appreciate, depend on, rely on, see to 等+it+ 从句 I would appreciate it if you could call me in advance.I hate it when people talk with their mouths full. 注意七：在think, imagine, suppose, guess, hope 等词后，以及在Im afraid等后， 可以用so 代替上文宾语从句所表达的肯定的意思，用not 表达否定的意思：I think so. /I dont think so=I think not.I hope so. /I hope not.(fear/ guess/ I am afraid)注意八：宾语从句的主语是that 时，that 不可省略：People say that that was how the Chinese first raised silkworms.注意九：介词后一般不跟that 引导的宾语从句但可跟wh-开头的词引导的宾语从句：Whether you will succeed depends on whether you will take pains.Please remind me of what he once said to me.但是but, except, besides, in 后可以跟that 引导的宾语从句，that 不省We know nothing about him except that he is from Beijing.Human beings are different from animals in that they can use languages as a tool to communicate.注意十:that 引导的宾语从句在口语或非正式文体中that 可省略，但一个动词后有两个或以上的由that 引导的宾语从句时，第一个that 可以省略，第二个起不省。The report shows (that) we are making some progress but that we need to make greater efforts.如果that 从句被短语等与主句分开，或者从句中含有另一个从句，that 不可省略。 They promised once again that this would not happen again. I dare say that if you dont work hard you will fail.二、表语从句一个句子作表语就叫表语从句。表语从句是解释说明主语的具体内容。What we dont doubt is that the patient will soon recover.Chances are that two out of ten youth are addicted to smoking.注意一：that, why 和because 的选择：1.表示原因的reason, cause 名词或从句作句子的主语时，其后的表语从句常用that 引导，不可误用because.1. The reason why he hasnt come is because he has not received the invitation. (that)2. I was late for school this morning. Thats why/because I stayed up too late last night.3. I stayed up too last night. Thats why/because I was very late for school this morning.(because引导表语从句时常用于Thats bcause结构中，说明产生上述结果的原因；why引导的名词性从句说明由上述原因导致的某种结果。注意二：1.当主语时suggestion, plan, order, idea 等词时， 表语从句的谓语要有虚拟语气，即should+动词原形，should可省略。My suggestion was that we (should) go to see the film together.2. as if 也可以引导表语从句：It looks as if it is going to snow.It looked as if he hadnt eaten for a week.三、主语从句：四个误区：误区一、误作特殊疑问句：When will they come back is puzzle./ When they will come back is a puzzle.误区二、机械套用：It was uncertain that when they did it./ It was uncertain when they did it.误区三、谓语动词形式误用复数：Why he made so many mistakes are not clear./ Why he made so many mistakes is not clear.误区四、与as从句混杂As/ It is known to us that the earth is round./ As/ It is known to us, the earth is round.注意一：that 引导的主语从句往往很长，放在句首显得头重脚轻。因此，常用it 作形式主语，代替that 引导的主语从句，将that 从句后置。1. It is +adj +that从句：1）adj: likely, possible, probable, certain, obvious 等+从句，时态一致2）adj: important, vital, necessary, natural, strange+从句+（should）+v原It is certain that our team can beat theirs.It is likely/possibly that I may not come to the party.It is strange that the excellent boy should have failed the exam.2. It is +n+that从句1）It is +no wonder+从句，时态一致2) It is +a pity/ a shame+从句+（should）+v原 It is a pity that you should have missed the wonderful film. He works hard. It is no wonder that he is so excellent.3. It is +done+that 从句1）done有：it is said that 类2）done 有：It is+一坚持、二命令、三建议、四要求的过去分词+that +should+do原 It is said/thought/believed that he will send his son abroad. It is suggested that he go there by air at once.4. It is the first time +that+从句+现在完成时 It is (high/about) time+that+从句+虚拟：1）did2) should+do 原 It is the first time that I have been here. It is time that we went/ should go to school.5. It +系动词/不及物动词+that +从句：（动词有，seem, happen, appear, turn out 等） It seemed that we had no hope to win the match. It so happened that he was out when I went to see him.注意二：主语从句作主语时，主语的谓语动词多用单数，而what 引导主语从句，主句的谓语动词形式要根据表语确定：What we needed then was money.What I want to buy are some books.四、同位语从句：注意一：同位语从句的位置与作用：同位语从句是名词性从句中一种，引起同位语从句的名词有：fact, news, hope, belief, order, truth, message, suggestion, word, idea, doubt, question, problem等。从句放在这些表示事实意义的名词之后，介绍它们的内容后作进一步的解释和补充说明。但如果主句的谓语部分过短时，可以吧谓语动词提前，使同位语从句与名词分开，以避免头重脚轻：Its my belief that her death wasnt an accident. Word came that she had won another gold medal.注意二：同位语从句的引导词：取决于名词的意思和从句的意思I have no idea where she comes back.He refused to answer the question how he got all his moneyThere is no doubt that life is like theatre.I have some doubt whether he really knows me.注意三：同位语从句的谓语动词形式Do you know who proved the truth that the earth goes around the sun?Soon we received the order that we should stop fighting at once.注意四：定语从句和同位语从句的区别：Nobody but Jim knew the news that you and his sister would get married.I dont believe the news that he told me.He expressed the hope that I wanted to express.He expressed the hope that he would visit China again.区别：1. That/ what1) ._he wanted to see was an end to all the armies in the world.2). _ we need more equipment is very clear. / Ill show you _ interests me most.2. What没范围which有范围 Can you tell me what language you can speak? Can you tell me which of the five working languages you can speak?3. if/ whether相同点：引导宾从，“是否” eg: I dont know if/whether he will come.不同点：只用whether: 1).引导主语、表语及同位语从句时2). 与or not直接连用时3). 用在to do前4). 用在动词discuss后 5). 用在介词后6). 宾语从句提到句首时例如：1. _he will win is all the