英语中的各种从句详解.docx

1、英语中的各种从句详解从句一名词性从句在句子中起名词作用的各种从句统称为名词性从句。这类从句在句中可担任主语、表语、宾语和同位语，名词从句可以分为主语从句、表语从句、宾语从句和同位语从句。1.主语从句在句子中担当主语的是一个句子，这个从句就叫作主语从句。主语从句可以由下列连词、连接代词和连接副词引导，且不能省略。连词：that, whether连接代词：what, whatever, who, whoever 等连接副词：when, where, how, why(1)由连词that, whether引导的主语从句连词that, whether在从句中的作用只是引导主语从句，它在从句中不担任成分

2、，不能省略，且由that, whether引导的主语从句，多用it多形式主语e.g That the earth is round is true.=It is true that the earth is round.地球是圆的，是一个事实。 Whether hell come or not hasnt been decided.= It hasnt been decided whether hell come or not.(2)由连接代词或连接副词引导的主语从句连接代词who, which和连接副词when, where, how, why都可以引导主语从句，它们分别在从句中担任主语、宾

3、语和状语，不能省略，翻译时，不能把它们译为疑问句，由它们引导的主语从句，也可以用形式主语it引导e.g Who let out the news remained unknown. =It remained unknown who let out the news.谁泄漏了那个消息仍旧无人知道。 When well start is not clear. =It is not clear when well start.我们何时出发还不清楚。(3)以关系代词what, whatever, whoever, whomever, whichever引导的主语从句不能用形式主语it引导，它们在句子中

4、担任成分，不能省略，语序为陈述语序。e.g What he said at the meeting is important.他在会上所说的事情是重要的。 Whoever leaves the office should tell me.无论是谁离开办公室都应该告诉我。(4)用it作形式主语的主语从句结构a. It is +名词+从句It is a fact that 事实是It is good news that 是好消息It is a question that 是个问题It is common knowledge that 是常识类似的名词还有：a pity；a wonder；a goo

5、d thing； no wonder； surprise等。例如：It is a mystery to me how it all happened.这一切是怎么发生的是个谜。It is common knowledge that the whale is not a fish. 鲸鱼不是鱼，这是常识。It is no surprise that Bob should have won the game. 鲍勃会赢得这场比赛，这不足为奇。b. It is +形容词+从句It is necessary that 有必要It is clear that 很清楚It is likely that 很

6、可能It is important that 重要的是类似的形容词还有：strange; natural; obvious; true; good; wonderful; possible; unlikely; quite; unusual; certain; evident; worth-while; surprising; interesting; astonishing, etc.例如：It is obvious that conductors and insulators are both important in industry.很明显导体和绝缘体在工业中都很重要。It is do

7、ubtful whether she will be able to come. 她是否能来令人怀疑。It was really astonishing that he refused to talk to you .他拒绝和你说话真是令人惊讶。 It is essential that he should be here by the weekend .周末之前，他应该到这里是必要的。It seems obvious that we can not go on like this.很明显我们不能这样下去了。c. It is +过去分词+从句It is said that 据说It is re

8、ported that 据报道It has been proved that 已证明It must be proved that 必须指出类似的过去分词还有：known; estimated; expected; believed; thought; hoped; noted; discussed; required; decided; suggested; demanded; made clear; found out,etc.例如：It is thought that he is the best player. 大家都认为他是最好的选手。It is estimated that the

9、vase is 2000 years old. 据估计这个花瓶有2000年的历史。It is used to be thought that a new star must be due to a collision between two stars. 过去一直认为新星是由于两颗星星之间碰撞产生的。It has not been made clear when the new road is to be opened to traffic.还没弄清楚这条路将开始通车。d. It +不及物动词+从句It seems that 好像是It happened that 碰巧It follows t

10、hat 由此可见It has turned out that 结果是类似的不及物动词还有：seem, appear, occur, follow, happen, turn out, etc.例如：It turned out that nobody remembered the address. 结果是无人记得那个地址。It now appears that they are in urgent need of help. 看起来他们急需帮助。 It does not matter if I missed my train, because there is another later.没有赶

11、上这趟火车没有关系，稍晚还有一趟。It happened that I saw him yesterday. 碰巧我昨天看见他了。当“及物动词 + 宾语”较短时，也可用这种结构。例如：It shocked me that Peter did not tell anybody where he was.让我吃惊的是彼得没有告诉任何人他在哪里。It does not interest me whether you go or not. 我对你去不去不感兴趣。e. It +某些固定结构+ 主语从句。It doesnt matter是无关紧要的It makes no difference毫无区别It

12、doesnt make too much difference that 关系不大It doesnt need to be bothered that不必担忧例如： It does not make any difference whether it rains or not . 下不下雨没什么分别。It does not make the least difference to me what you do.对我来说你做什么都无关紧要。2. 宾语从句用作宾语的从句叫宾语从句。1.引导宾语从句的关联词有三类：(1) 从属连词that。如： He told us that he felt ill

13、. 他对我们说他感到不舒服。 I know he has returned. 我知道他已经回来了。注： that在引导宾语从句时也并不是任何情况下都可以省略。在以下情况下，that不能省略。 1. Everybody could see what happened and that Tom was frightened. 大家都会看出所发生的事情并知道Tom非常害怕。and连接两个宾语从句，that宾语从句放在and的后面时，that不能省略。 2. I know nothing about him except that he is from the south. 对他我一无所知，只知道他是

14、南方人。that引导的宾语从句作介词宾语时，that不能省略。 3. That he ever said such a thing I simply dont believe. 我简直不相信他曾说过这样的话。that从句位于句首时，that不可省略。 4. We decided, in view of his special circumstances, that we would admit him for a probationary period. 鉴于他的特殊情况，我们决定应允他一段试用期。主句谓语动词与that从句之间有插入语，that不可省略。(2)从属连词if/whether。如

15、：I doubt whether he will succeed. 我怀疑他是否会成功。I dont know if you can help me. 我不知道你能否帮助我。(3)连接代词who, whom, whose, what, which, whoever, whatever, whichever 连接副词 where, when, how, why。 e.g Who or what he was, Martin never learned. 他是什么人？他是干什么的？马丁根本不知道。I wonder what hes writing to me about. 我不知道他要给我写信说什么事。 Ill tell you why I asked you to come. 我会告诉你我为什么要你来。2. 介词宾语从句宾语从句也可用作介词的宾语。如： He was deeply displeased by what had occurred that day.他对那天发生的事感到很不快。 I walked over to wh