名词性从句用法归纳

1、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）。名词性从句在复合句中能担任 : 主语、宾语、表语、同位语、介词宾语等。 名词性从句分为：主语从句、宾语从句、表语从句和同位语从句。一、引导名词性从句的连接词引导名词性从句的连接词可分为三类：1、从属连词（ 5 个）：（1）that 无词义，在从句中不做成分，在宾语从句或表语从句中that 有时可以省略（2）whether ，if 有词义，在从句中不做成分（ whether ，if 均表示 “是否 ”之意，表明从句内 容的不确定性）不可以省略（3）as if, as though （均表示 “好像”， “似乎 ”之意）

2、在从句中不做成分2、连接代词（9 个）：what, whatever, who, whoever, whom, whomever, whose, which, whichever , 有词义， 在从句中做成分， 不可以省略 （ who what which 在从句中做主语、 宾语、 其中 what 指代没有范围的事物， which指代有范围的事物，表 选择哪一个” whom做宾语whose做定 语）3、连接副词（ 7 个）： when, where, how, why, whenever, wherever, however 有词义，在从句 中做状语，不可以省略4、that 省略的情况：（ 1

3、）定语从句中做宾语（ 2） that 引导宾语从句时（ 3） that 引导表语从句时（ 4）主语从句中 it 做形式主语， that 从句置于句末时5、that 不可省略的情况：（ 1）定语从句中做主语（ 2）由 that 引导主语从句放句首时（ 3） that 引导同位语从句时（ 4）宾语从句中 i it 做形式宾语，真正的 that 宾语从句中 that 不可以省略ii 一个句子有两个或多个并列的宾语从句时，引导第二个和以后几 个句子中的 that 不可以省略iii 与动词相隔的宾语从句，不可以省略iv that 引导的宾语从句放在句首时，不可以省略二. 主语从句1、主语从句：作句子主语

4、的从句叫主语从句。主语从句通常由下列词引导：1）从属连词 that， whether 等；2） 连接代词 what ， who ， which ， whatever ， whoever ， whom 等；3）连接副词 how， when ， where， why 等。2、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。例如：What he wants to tell us is not clear.Who will

5、 win the match is still unknown.It is known to us how he became a writer.Where the English evening will be held has not yet been announced. 注意：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。常用句型如下：(1) It + be + 名词 + that 从句： It is a fact that 事实是 It is an honour that 非常荣幸 It is m

6、on kno wledge that-是常识It is a pity that 遗憾(2) It + be + 动词的过去分词 + that 从句:It is said that 据说It is reported that 据报道It has been proved that 已经证明It is believed that人们认为It is supposed that据猜测(3) It + 不及物动词( vi) + that 从句：It seems that 似乎It happened that 碰巧 It appears that 似乎(4) It + be + 形容词 + that 从句I

7、t is natural that很:自然 It is strange that奇怪的是 注意: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，谓语动词要用虚拟语气“(should) +do, 常用的句型有：It is necessary (important, natural, strange, etc.) thatIt is suggested (requested, proposed, desired, etc.) that3、It 作形式主语和 it 引导强调句的比较 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。 it引导的强调句则是对句子某

8、一部分进行强调，无论强调的是什么成分，都可用连词that引导，被强调部分指人时也可用 who/whom 。例如：a) It is a pity that you didn't go to see the film.b) It doesn't interest me whether you succeed or not.c) It is in the morning that the murder took place. (强调句型)d) It is John that broke the window. (强调句型)4、注意：since, if不能引导主语从句， 但当it做形式

9、主语，主语从句放在句末时，if, whether 均可5、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：正确表达： It is said that President Jiang will visit our school next week. 错误表达： 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：正确表达： It occur

10、red to him that he failed in the examination. 错误表达： That he failed in the examination occurred to him.(4) It doesn ' t matter how/whether结构中的主语从句不可提前。例如：正确表达： It doesn't matter whether he is wrong or not. 错误表达： Whether he is wrong or not doesn't 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：正确表达

11、： Is it likely that it will rain in the evening? 错误表达： Is that will rain in the evening likely?6、what 与 that 在引导主语从句时的区别 what 引导主语从句时在句时在从句中充当句子成分，如主语宾语表语，而 that 则 不然。例如：a） What you said yesterday is right.b） That she is still alive is a consolation三、表语从句表语从句：在复合句中，位于系动词之后作表语的从句叫表语从句。 引导表语从句的关 联词与引导

12、主语从句的关联词大致一样，表语从句位于连系动词后，有时用 as if 引导。 可以接表语从句的系动词有be ,look , remain （保持）,seem等常用的还有 the reason is thatIt-is because-It appears/seems that It happens thatIt-turns out that（结果是 ）等结构由从属连词，连接代词，连接副词引导，其中 that 常常可以省略 由 as if， as though 引导 It looks as ifIItseems as if Iwhy, because 都可以引导表语从句，但 why 强调结果，

13、because 强调理由 当主语为 suggestion, order, requirement, advice, request, demand 等这类名词时，表语从句用 虚拟语气（ should）do if 不能引导表语从句注意：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 . 【注意】 whether 可引导表语从句，但与之同义的 if 却通常不用于引导表语从句。四、同位语从句1、 同位语从句说

14、明其前面的名词的具体内容。同位语从句通常由that 引导， that 不可以省 略由 whether 引导，不可用 if2、 可用于同位语从句的名词有 belief、advice、demand、doubt （怀疑） 、possibility、though 、 proposal、case、fact、hope、idea、information 、message、news、order、problem 、promise、 question、request、suggestion、truth 、wish、word 等。例如：The news that we won the game is exciting

15、.I have no idea when he will e back home.The thought came to him that Mary had probably fallen ill.3、在no idea后用wh-疑问词引导4、同位语从句与定语从句的区别（1）定语从句中的 that 既代替先行词，同时以在从句中作某个成分（主语或宾语），而同位语从句中的 that 是连词，只起连接主句与从句的作用，不充当句中任何成分。（2）定语从句是形容词性的，其功能是修饰先行词，对先行词加以限定，描述定的性质或特 征；同位语从句是名词性的，其功能是对名词进行补充说明。例如：1）The news

16、that he told me is that Tom would go abroad next year. （他告诉我的消息是汤姆明 年将出国。 ） （第一个 that 引导的从句是定语从句， that 在从句中作宾语）2）The news that Tom would go abroad is told by him. （汤姆将出国的消息是他讲的。 ）（同位语 从句， that 在句中不作任何成分） 五、宾语从句 宾语从句：名词从句用作宾语的从句叫宾语从句。由从属连词、连接代词、连接副词引导。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

17、任任何成分，在口语或非正式的文体 中常被省去，但如从句是并列句时,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 everything while others are good in nothing.注意： 在 dema nd、order (命令)、suggest、decide、in sist (坚持)，desire, urge, advice, propose， require， request, mand (命

18、令) , 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.The mander ordered that troops (should) set off at once.2. 用 who ， 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。例如：I want to

19、know what he has told you.She always thinks of how she can work well.She will give whoever needs help a warm support.3. 用 whether 或 if 引导的宾语从句，其主语和谓语的顺序也不能颠倒，仍保持陈述句语序。此外， 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：a. 引导主语从句并在句首时； b. 引导表语从句时； c . 引导从句作介词宾语时； d. 从 句后有“or not时；e.后接动词不定式时。例如：Whe

20、ther there is life on the moon is an interesting question.Everything depends on whether we have enough money.I wonder whether he will e or not.Can you tell me whether to go or to stay?4. 注意宾语从句中的时态呼应，当主句动词是现在时，从句根据自身的句子情况，而 使用不同时态。例如：I know (that) he studies English every day. (从句用一般现在时)I know (that

21、) he studied English last term. (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) 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。例如：The teacher told us that Tom had left us

22、 for America 5. think, believe, imagine, suppose ， guess, expect, fancy, consider 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。 例如：We don't think you are here. 我们认为你不在这。I don ' t believe he will do so我相信他不会这样做。6、后面不能接 that 从句的动词有： condemn 谴责，判刑 force 强迫 take 拿走 forgive 原谅 dislike 不喜欢 r

23、efuse 拒绝 let like love help admire 羡慕 allow celebrate cause注：以上动词后不能接 that 从句，但可以用不定式，动名词做宾语。六、whether 与 if 均为 "是否 "的意思。但在下列情况下，只可用 whether ：1. whether 引导主语从句并在句首时，只能用 whether ，当 it 做形式主语，主语放句首 时， whether ，if 均可eg:whether he can e to the party on time depends on the traffic2. 引导表语从句eg:The

24、question is whether we can get in touch with her3. whether 从句作介词宾语e.g:It depends on whether he will e.4.if 与 whether 都可以与 or not 连用，但后面紧跟 or not 时只能用 whetherWe didn't 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. 引导同位语从句Whether he w

25、ill e is not clear.6. 后接不定式时Eg I don 't know whether to go.7. 在 discuss后只能用 whether 注意：（1）大部分连接词引导的主语从句都可以置于句末，用it 充当形式主语。 It is notimportant who will go.It is still unknown which team will win the match.（2）whether 从句中不能有否定式，而if 可以I don 't care if he doesn't e.七、名词性that-从句（1）由从属连词that引导的

26、从句叫做名词性that-从句。That只起连接主句和从句的作用，在从句中不担任任何成分，本身也没有词义。名词性 that-从句在句中能充当主 语、宾 语、表语、同位语和形容词宾语，例如：主语： That she is still alive is her luck. 她还活着全靠运气。宾语：John said that he was leaving for London on Wednesday.约翰说他星期三要到伦敦去。表语： The fact is that he has not been seen recently. 事实是近来谁也没有见过他。 同位语： The fact that he

27、 has not been seen recently disturbs everyone in his office. 近来谁也没有见过他，这一事实令办公室所有的人不安。形容词宾语： I am glad that you are satisfied with your job.2）That-从句作主语通常用it作先行词，而将that-从句置于句末，例如：It is quite clear that the whole project is doomed to failure. 很清楚，整个计划注定要失败。 It's a pity that you should have to lea

28、ve. 你非走不可真是件憾事。用it作形式主语的that-从句有以下四种不同的搭配关系：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 bee n decided that已决定c. It + be + 名词 + that-从句It is mon knowl edge that 是常

29、识It is a surprise 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 happe ns that碰巧It occurred to me that我突然想起 八、名词性wh-从句1) 由wh-词引导的名词从句叫做名词性wh-从句。Wh-词包括 who, whom,. whose,whoever, what, whatever, which, whichever 等连接代词和 where, when, how, why 等连接副词。 Wh-从句的语法功能除了和that-从句一样外，还可充

30、当介词宾语、宾语补语和间接宾语等，例如：主语： How the book will sell depends on its author. 直接宾语： In one's own home one can do what one likes. 间接宾语： The club will give whoever wins a prize.俱乐部将给得胜者设奖。表语： My question is who will take over president of the Foundation. 宾语补足语： She will name him whatever she wants to.同位语：

31、 I have no idea when he will return. 形容词宾语： I'm not sure why she refused their invitation. 介词宾语： That depends on where we shall go.2) Wh-从句作主语也常用先行词it做形式主语，而将 wh-从句置于句末，例如：It is not yet decided who will do that job.It remains unknown when they are going to get married.九、if, whether引导的名词从句1)yes-n

32、o 型疑问从句从属连词 if, whether 引导的名词从句是由一般疑问句或选择疑问转化而来的，因此也分别被称为yes-no型疑问句从句和选择型疑问从句，其功能和wh-从句的功能相同，例如：主语： Whether the plan is feasible remains to be proved.宾语： Let us know whether / if you can finish the article before Friday.表语： The point is whether we should lend him the money. 同位语： They are investigati

33、ng the question whether the man is trustworthy. 形容词宾语： She's doubtful whether we shall be able to e.介词宾语： I worry about whether he can pass through the crisis of his illness.2)选择性疑问从句选择性疑问从句由关联词if/whethero或whetheror not构成，例如：Please tell me whether / if they are Swedish or Danish.I don't care

34、 whether you like the plan or not.if 和 whether 的区别：1、在动词不定式之前只能用 whether 。如：例 8 I can 't decide whether to stay.2、 在whether or not的固定搭配中。如：例 9 I want to know whether it's good news or not .3 、在介词后，只能用 whether 。如：例 10 His father is worried about whether he lose his work . 。4、 宾语从句放在句首表示强调时，只能用whether 。如：Whether thi s is true or not, I really don't know.（例 11 Whether they can finish the work on time is still a problem . 他们是否能准时完成 这项工作还是个问题。此例为主语从句，有误，感谢指出）5、用 if 会引起歧义时，只用