1、主语从句,说出划线部分的成分,1）That the sea covers about three-fourths of the earths surface is well known. 2）Which design is more practical is still a question. 3）What we call a hovercraft is a means of transport with neither wheels nor wings. 4）It is well known that the sea covers about three-fourths of the ear
2、ths surface. 5）It is still a question which design is more practical.,一主语从句,主语从句是在复合句中充当主语的从句，通常放在主句谓语动词之前或由形式主语it代替，而本身放在句子末尾。What或how引出的主语从句具有疑问意义，但必须采取陈述词序，that引出的具有陈述意义。,引导主语从句的连词主要有:,that,Whether,疑问词,一.由 that 引导的主从: 1. That we shall be late is certain. 2. _ is known to all. (地球是圆的) 3. _ _is a p
3、ity. (你错过了这次机会) that 不作成分，无意义, 但不能省略. 后接一个完整的陈述句. 注：that 引导的主语从句作主语，谓语用单数,That you missed the chance,That the earth is round,It 作形式主语代替主语从句，主要是为了平衡句子结构，主语从句的连接词没有变化。 That we need time is obvious. =It is obvious that we need time It is a pity that you didnt go to see the film. It doesnt interest me w
4、hether you succeed or not.,that 引导的主从，常用形式主语it 代替，that 从句后移。,用it 作形式主语的结构,(1) It is 名词 从句 It is a fact that 事实是 It is an honor that 非常荣幸 It is common knowledge that 是常识 (2) It is 形容词 从句 It is natural that 很自然 It is strange that 奇怪的是 (3) It is 不及物动词 从句 It seems that 似乎 It happened that 碰巧 It appears
5、that 似乎 (4) It 过去分词 从句 It is reported that 据报道 It has been proved that 已证实 It is said that 据说,二. What 引导的主从， (1)what作主语，宾语或表语，表语 译为“什么”“的东西/情况/话/” What we need is time. What he said is true.,(2)What 引导的主从，谓语动词视后面的名词而定。 What we need time. What he gave me _two books.,is,are,what 引导主语从句时在从句中充当句子成分，如主语、
6、宾语、表语，有含义； 而that 则无含义，也不充当任何成分,不可省略。 1) _you said yesterday is right. 2) _she is still alive is a good thing.,It,It,What,That,what 与that 在引导主语从句时的区别,is right what you said yesterday.,is a good thing that she is still alive.,what / that 填空 a._ he said at the meeting surprised us. b._ he spoke（发言） at
7、the meeting surprised us.,What,That,典型例题,3. 由whether引导的主从: e.g. Whether hell be able to come is not yet known. Whether we will succeed is still a question. 主语从句不能用if来引导; Ex:1.是否我们要参加这次会议仍未被决定。 Whether we shall attend the meeting hasnt been decided yet.,陈述语序,4. 疑问词引导的主语从句 what; which; who; whom; when
8、; where; why; how 原则:缺什么补什么 What he said at the meeting surprised us. Who will win the game is not clear. Where he will go is unknown. Why they have not left yet puzzled me. How we can get there is a problem.,1._ makes this shop different is that it offers more personal services. A.What B. Who C. Wh
9、atever D. Whoever 2._I can pay back the help that people give me makes me very happy. A.Where B.What C.That D.How 3.Its not clear _ was responsible for the accident. A.Who B.What C.How D.That,A,Ex.,C,A,名词性从句中的虚拟语气的问题,(1)在主语从句中用来表示惊奇、不相信、惋惜、理应如此等,谓语动词用虚拟语气“(should) +do“,常用的句型有: It is necessary (impor
10、tant, natural, strange) that从句 It is a pity(a shame, no wonder) that从句 It is suggested (requested, proposed, desired)that从句,(1)在主语从句中用来表示惊奇、不相信、惋惜、理应如此等,谓语动词用虚拟语气“(should) +do“,常用的句型有: It is necessary (important, natural, strange) that从句 It is a pity(a shame, no wonder) that从句 It is suggested (reque
11、sted, proposed, desired)that从句,. 主语从句不可位于句首的五种情况：,主语从句不可位于句首的五种情况：,（1）if 引导的主语从句不可居于复合句句首。 （2）It is said /reported结构中的主语从句不可提前。例如： It is said that President Jiang will visit our school next week. That President Jiang will visit our school next week is said. （3）It happens/occurs结构中的主语从句不可提前。例如： It oc
12、curred to him that he failed in the examination. That he failed in the examination occurred to him.,（4）It doesnt matter how/whether 结构中的主语从句不可提前。例如： It doesnt matter whether he is wrong or not. Whether he is wrong or not doesnt matter. （5）含主语从句的复合句是疑问句时，主语从句不可提前。例如： Is it likely that it will rain in
13、 the evening? Is that will rain in the evening likely?,exercises,Choose the best answer: 1.what / that a. he said at the meeting surprised us. b._ he spoke at the meeting surprised us. 2. if / whether _you go or stay at home wont make any differences. 3. What a pity _is _you didnt arrive by daylight
14、. A. there, because B. it, that C. he, when D. that, for,What,That,Whether,B,4. he saw both surprised and frightened him. A.When B. That C. What D. Whom,C,5. It is not easy to decide a report about unidentified flying objects is true or not. A. whether B. that C. if D. which,A,6. quality should come first is not very clear to every member in our factory.,A,Goodbye！,
