A名词性从句.docx

1、A名词性从句从句从句是相对于主句而言的，即它是从属于某一个主句，虽然具有一般句子的结构，但只能作整个句子的某一成分而不能单独作一个句子。在英语中，按照从句所表达意思的内容，主要分为三大从句，即：名词性从句（包括主语从句，宾语从句，表语从句，同位语从句）、形容词性从句（即定语从句）、副词性从句（即状语从句,包括时间、条件、结果、目的、原因、让步、地点、方式等）。主语从句用作主语，如：That the earth is round is true. 宾语从句用作宾语。如：Do you know where he lives?表语从句用作表语，如：My opinion is that you sho

2、uld not go alone. 同位语从句用于解释说明前面的名词。如：The fact that the earth is round is true. （that从句用于解释说明the fact）定语从句相当于一个形容词，用于修饰前面的名词。如：The student who answered the question was John. 回答问题的学生是John. 状语从句相当于一个副词，如：When it rains, I usually go to school by bus. 天下雨时，我通常坐公共汽车上学。（时间状语）If he comes tomorrow, you will

3、 see him. 如果他明天来，你就可以看见他。（if 引导的条件状语从句，其结构为：if +状语从句，主句）。要注意在状语从句中有一个规则是“主将从现”，即主句是将来时，则从句要用一般现在时表示将来。从句的特征：1. 从句句首一般有关系词（引导词连接词、关联词）。A类： that B类： if, whether C类： what,when,where,who,why,whose,which how,whom D类：since,as,while,before,after,till,until once,whenever,wherever,because,unless though,altho

4、ugh, E类：as soon as, as long as, so long as, in case, so that, in order that, so.that, such.that, as if, each time,next time, the first time,the last time by the time, from the time.2. 具有一般句子的结构，并且句子的语序永远是陈述语序。特别是当连词为特殊疑问词时，此时，必须明了的是，从句并非特殊疑问句。因而，从句不得用问句形式，而必须用陈述语序。 (1)I asked him what he was doing t

5、here. (2)They wanted to know where I had been. (3)The teacher wondered why he was late for class. (4)He told us whom the house belonged to. (5)I felt surprised how he made it.3. 从句的时态要与主句相呼应。 A:主句是现在时，从句任意I know (that) he studies English every day. （从句用一般现在时） I know (that) he studied English last te

6、rm. （从句用一般过去时） I know (that) he will study English next year. （从句用一般将来时） I know (that) he has studied English since 1998. （从句用现在完成时） (1)He always helps me with my English when he has time. (2)She always says that she had a tough life in the past. (3)Nobody knows what he will do in the future. （4)The

7、 boys are talking about the football game which was shown on TV yesterday. (5)The students are talking while the teacher is speaking in the class. B: 当主句动词是过去时态（could, would除外），从句则要用相应的过去时态，如一般过去时，过去进行时，过去将来时等；当从句表示的是客观真理，科学原理，自然现象，则从句仍用现在时态。 The teacher told us that Tom had left us for AmericaThe t

8、eacher told us that the sun sets in the west. (1)He told me on the phone that he was driving on the highway. (2)They wanted to know whether they had passed the exam. (3)Students were discussing what they would do in the future. (4)I wondered where the boy came from. (5)We were cleaning the room whil

9、e he was playing the video game.C.主句是一般将来时，从句用一般现在时（主将从现）英语的主从复合句中，主句为现在将来时，从句则必须是一般现在时，此时的从句多作为一种先决条件，表明无论是现在还是将来，只要条件满足，则主句的动作就将发生。 (1)We will have a meeting as soon as he comes back. (2)We will have an outing if it doesnt rain tomorrow. (3)They are going to have a football game with Class 3 when

10、they are free. (4)Nobody will help him if he keeps cheating. (5)She will buy some clothes as long as she has money.1.主语从句 A:What we need is your passion for learning English. B:Why he was late still remianed a question. C:Whether we should rebuild our hometown in the original place is being discusse

11、d.2.宾语从句 A:They said that they had finished their work on time. B:I told them I would be back in an hour. C:The teacher wondered where the students had gone.3.表语从句 A:He is what he was before. B:She appeared that she had nothing to do with it. C:Their idea sounded that they had no way out.4.状语从句 A:Th

12、ey were watching TV when I came in.（时间） B:He knows where we can find a hotel.(地点） C:Since we have not enough money,we will have to give up this plan.(原因） D:She would do it again if she found a mistake in her homework.（条件） E:The old man gets up so early that he can have enough time to exercise.（目的） F

13、:The box is so heavy that nobody can move it.(结果） G:One should be punished if he breaks the law,no matter who he is.(让步） H:He walks as if he is drunk.(方式） I:You dont study so hard as Tom does.(比较） 主从复合句中从句的主语省略情况多出现在宾语从句中，条件是：1)连词为特殊疑问词或if,whether2)从句含有情态动词或将来时3)从句的主语与主句的主语或宾语相同,可分为下列两种情况： a.当主句的主语与

14、从句的主语相同时，从句的主语可省略，用动词不定式替代：We didnt know where we should go.We didnt know where to go.He asked how he would learn English well.He asked how to learn English well. b.主句的宾语和从句的主语相同时，从句的主语可用动词不定式替代：He asked me where I would go.He asked me where to go.They told him how he could make her happy.They told

15、him how to make her happy.其它情况:I saw a boy who was playing football in the street yesterday.I saw a boy playing football in the street yesterday.1、名词词从句（包括主语从句，宾语从句，表语从句，同位语从句）2、定语从句（形容词从句）3、状语从句（副词性从句，包括时间，地点，结果，目的，原因等）名词性从句在句子中起名词作用的句子叫名词性从句 (Noun Clauses）。 名词性从句的功能相当于名词词组, 它在复合句中能担任主语、宾语、表语、同位语、介

16、词宾语等，因此根据它在句中不同的语法功能，名词性从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。 一、引导名词性从句的引导（连接）词分类引导名词性从句的连接词可分为三类： 一般连接词（4/5个）：that （宾语从句或表语从句中that有时可以省略） whether，(if)（均表示“是否”表明从句内容的不确定性） as if ,as though （均表示“好像”，“似乎”） 以上在从句中均不充当任何成分 连接代词（9个）：what, whatever, who, whoever, whom, whomever, whose, which, whichever 连接副词（7个）：w

17、hen, where, how, why, whenever, wherever, however 主语从句： 名词从句用作主语的从句叫主语从句。从句连接词20个，没有if.that在句中无词义，只起连接作用；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，在从句中充当从句的成分。注：whom、who指人，what指物，whatever，whoever表示泛指意义。What he wants to tell us is not clear. Who will win the match is still unknown. It is known to us how he becam

18、e a writer. Where the English evening will be held has not yet been announced. 大部分引导连接词引导的主语从句有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。Who will go is not important .It is not important who will go. Which team will win the match is still unknown.It is still unknown which team

19、will win the match.常用句型如下： a. It + be +形容词+ that-从句 It is necessary that有必要 It is important that重要的是 It is obvious that很明显 b. It + be + -ed 分词+ that-从句 It is believed that人们相信 It is known to all that众所周知 It has been decided that已决定 c. It + be +名词+ that-从句 It is common knowledge that是常识 It is a surpr

20、ise that令人惊奇的是 It is a fact that事实是 d. It +不及物动词+ that-从句 It appears that似乎 It happens that碰巧 It occurred to me that我突然想起众所周知1) It is known to us that 2) As is known to us, 3) what is known to us is thatIt is necessary (important, natural, strange, etc.) that It is suggested (requested, proposed, de

21、sired, etc.) that 注意后两种，在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，从句谓语动词要用虚拟语气“(should) +do”，宾语从句名词从句用作宾语的从句叫宾语从句。从句连接词21个1. 由连接词that引导的宾语从句 由连接词that引导宾语从句时，that在句中不担任任何成分，在口语或非正式的文体中常被省去，但如果从句是并列句时,第二个分句前的that不可省。例如： He has told me that he will go to Shanghai tomorrow.We must never think (that) we are good in e

22、verything while others are good in nothing. 注意：在demand、order、suggest、decide、insist, desire, request, command, doubt等表示要求、命令、建议、决定等意义的动词后，宾语从句常用“（should）+ 动词原形”。例如： I insist that she (should) do her work alone. 我坚持要她自己工作。 The commander ordered that troops (should) set off at once. 司令员命令部队马上出发。 2. 用wh

23、o，whom, which, whose, what, when, where, why, how, whoever, whatever, whichever等关联词引导的宾语从句相当于特殊疑问句，应注意句子语序要用陈述语序。I want to know what he has told you. 我想知道他告诉了你什么。 She always thinks of how she can work well. 她总是在想怎样能把工作做好。 She will give whoever needs help a warm support. 凡需要帮助的人，她都会给予热情的支持。 think, be

24、lieve, imagine, suppose等等动词引起的否定性宾语从句中，要把上述主句中的动词变为否定式。即将从句中的否定形式移到主句中。We dont think you are here. 我们认为你不在这。 I dont believe he will do so. 我相信他不会这样做。表语从句在复合句中，位于系动词之后作表语的从句叫表语从句。表语从句的连接词21个其基本结构为：主语 + 系动词 + that从句。 The fact is that we have lost the game. 事实是我们已经输了这场比赛。 Thats just what I want. 这正是我想要

25、的。 This is where our problem lies. 这就是我们的问题所在。 That is why he didnt come to the meeting. It looks as if it is going to rain. 看上去天要下雨了。 需要注意的，当主语是reason时，表语从句要用that引导而不是because。例如： The reason why he was late was that he missed the train by one minute this morning . 同位语从句同位语从句说明其前面的名词的具体内容。同位语从句通常由tha

26、t引导，没有实际意义，不充当句子成分，一般不能省略。 可用于同位语从句的名词有advice、demand、doubt、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等。The news that we won the game is exciting.I have no idea when he will come back home. The thought came to him that Mary had probably f

27、allen ill. 不可省略的连词： 1. 介词后的引导词 2. 引导主语从句和同位语从句的引导词不可省略。 That she was chosen made us very happy. We heard the news that our team had won.whether与if 在作“是否”的意思讲时在下列情况下一般只能用whether，不用if： 1.引导主语从句或在句首时：eg:whether he can come to the party on time depends on the traffic.Whether there is life on the moon is

28、 an interesting question.2. 引导表语从句 eg:The question is whether we can get in touch with her 3. whether从句作介词宾语 eg:I am thinking about whether I should quit my present job Everything depends on whether we have enough money. 4.从句后有“or not”时we didnt know whether or not she was ready.（此时只能用whether） I wonder whether/if the news is true or not.（此时则二者都可以用） 5. 后接动词不定式时。 Can you tell me whether to go or to stay? 6. 用if会引起歧义时，只用whether。Could you tell me if you know the answer ? 这句话有两种意思：“你能告诉我是否知道答案吗？”或“如果你知道答案，请告诉我，好吗？”。如用whether可避免歧义.