1、 比较：whether与if 均为”是否”的意思。 但在下列情况下，whether 不能被if 取代： 1. whether引导主语从句并在句首 2. 引导表语从句 3. whether从句作介词宾语 4. 从句后有”or not” Whether he will come is not clear. 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 not important who will go. It is still unknown which team will win the match. 名词性that-从句 1）由从属连词that引导的从句叫做名词
2、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 he is still alive is sheer luck. 他还活着全靠运气。 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 has n
3、ot 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。 Its a pity that you should have to leave. 你非走不可
4、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从所周知 It has been decided that已决定 c. It + be +名词+ that-从句 It is common knowledge that 是常
5、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-分句 It appears that似乎 It happens that碰巧 It occurred to me that我突然想起 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，还可充当介
6、词宾语、宾语补语和间接宾语等，例如： How the book will sell depends on its author. 书销售如何取决于作者本人。 直接宾语：In ones own home one can do what one likes. 在自己家里可以随心所欲。 间接宾语：The club will give whoever wins a prize. My question is who will take over president of the Foundation. 我的问题是谁将接任该基金会主席职位。 宾语补足语：She will name him whateve
7、r she wants to. 她高兴给他起什么名字就取什么名字。 I have no idea when he will return. 我不知道他什么时候回来。Im not sure why she refused their invitation. 我尚不能肯定她为什么拒绝他们的邀请。 介词宾语： That depends on where we shall go. 那取决于我们去哪儿。 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. 还没决定谁做这项工作。 It re
8、mains unknown when they are going to get married. 他们何时结婚依然不明。 if, whether引导的名词从句 1）yes-no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：Whether the plan is feasible remains to be proved. 这一计划是否可行还有等证实。Let us know whether / if you can finish the article
9、before Friday. 请让我们知道你是否能在星期五以前把文章写完。The point is whether we should lend him the money. 问题在于我们是否应该借钱给他。They are investigating the question whether the man is trustworthy. 他们调查他是否值得信赖。 Shes doubtful whether we shall be able to come. 她怀疑我们是否能够前来。 I worry about whether he can pass through the crisis of
10、 his illness. 我担心他是否能度过疾病的危险期。 2）选择性疑问从句 选择性疑问从句由关联词if/whetheror或whetheor not构成，例如： Please tell me whether / if they are Swedish or Danish. 请告诉我他们是瑞典人还是丹麦人。 I dont care whether you like the plan or not.我不在乎你是否喜欢该计划。 否定转移 1） 将think, believe, suppose, expect, fancy, imagine等动词后面宾语从句的否定词转移到主句中，即主句的谓语动词
11、用否定式，而从句的谓语动词用肯定式。 I dont think I know you. 我想我并不认识你。 I don t believe he will come. 我相信他不回来。 注意：若谓语动词为hope,宾语从句中的否定词不能转移。 I hope you werent ill. 我想你没有生病吧。 2） 将seem, appear 等后的从句的否定转移到前面。 It doesnt seem that they know where to go. 看来他们不知道往哪去。 It doesnt appear that well have a sunny day tomorrow. 看来我们
12、明天不会碰上好天气。 3） 有时将动名词，介词短语或整个从句的否定转变为对谓语动词的否定。 I dont remember having ever seen such a man. 我记得从未见过这样一个人。 （not否定动名词短语 having） Its not a place where anyone would expect to see strange characters on the street. 在这里，人们不会想到在街上会碰上陌生的人。 （anyone 作主语，从句中的谓语动词不能用否定形式。） 4） 有时状语或状语从句中否定可以转移到谓语动词前。 The ant is no
13、t gathering this for itself alone. （否定状语） 蚂蚁不只是为自己采食。 He was not ready to believe something just because Aristotle said so. （否定because状语） 他并不因亚里斯多德说过如何如何，就轻信此事。 She had not been married many weeks when that mans younger brother saw her and was struck by her beauty. （否定状语many weeks） 她结婚还不到几个月，这个人的弟弟就
14、看见她了，并对她的美貌着了迷。 （ ） made a promise _ he would buy me a ten speed bicycle as a birthday present. A. which B. when C. that D. how （ ） asked the young man_. A. whats wrong with him B. what was wrong with him C. whats trouble D. how was he （ ） you tell me _the post office? A. how I can get to B. how can
15、 I get to C. where I can get to D. where can I get to （ ） question is _it is worth doing. A. howB. whether C. that D. what （ ） is known to all _the sun rises in the east. A. what B. whichC. thatD. when （ ）6._you have done might do harm to him. A. That B. What C. WhichD. This （ ） and get your coat. I
16、ts _you left it. A. thereB. where C. there where D. where there （ ） you know_? A. who is she B. what she isC. whom she is D. what is she （ ）9._mathematics is the base of all other sciences. A. This is becauseB. This is thatC. It is thatD. Because （ ）10. I dont know_. A. How old is he B. he is how ol
17、dC. how old he isD. is he how old （ ） was under the dark _Fred found the watch. A. whereB. thatC. which D. there （ ） suggestion _we should make a bicycle trip to collect money for the disabled is worth considering. A. which B. that C. whatD. in which （ ） important thing is _improve our English. A. h
18、ow we can B. how can we C. what we can D. what can we （ ） must do _to help him. A. that we can B. which we can C. what we can D. those we can （ ） home town is no longer _. A. what it is B. which it was C that it used to be D. what it used to be （ ） method _you solved the problem is good. A. with tha
19、t B. thatC. with which D. which （ ） was said _was how the Chinese first raised silkworms. A. that B. which C. that that D. of that （ ）18._do you think is right _difficulties you may have ? A. What, whateverB. That, that C. Which, whatD. How, whatever （ ）19._leaves the room last ought to turn off the
20、 lights. A. AnyoneB. The person C. WhereverD. Whoever （ ）20._breaks the law should be punished. A. The personB. Who C. WhoeverD. Anyone （ ）21._will go makes no difference. A. WhetherB. WhoC. What D. How （ ）22._shes coming or not doesnt matter too much. A. WhyB. WhoeverC. WhenD. Whether （ ）23._they w
21、ill start has not been decided yet. A. WhyB. Whoever C. WhenD. Whether （ ）24._he did that wasnt quite clear. 篇二：高中英语基础语法复习：名词性从句 语法复习： 名词性从句相当于名词，可分别作主句的主语、表语、宾语和同位语。因此，名词性从句厅分为主语从句、表语从句、宾语从句和同位从句。 （一）引导名词性从句的连接词 1、连接代词：who, whose, whom, what, which。有词义，在从句中担任成分，如主语、表语、宾语、或定语等。 2、连接副词：when, where, w
22、hy, how。有词义，在从句中担任成分，作状语。 3、连接词：that, whether, if, as if。that 无词义，在从句中不担任成分，有时可省略；if （whether）, as if虽有词义，但在从句中不担任成分。连接代词与连接副词在句中不再是疑问句，因而从句中谓语不用疑问式。连接代词与连接副词在从句充当句子成分，连接词whether 和if（是否），as if（好象）在从句中不充当句子成分，只起连接作用。根据句义，如果连接代词与连接副词，whether、if 和as if都用不上时，才用that作连接词（that本身无任何含义）。 （二）主语从句 1、主语从句在复合句作主
23、语。 Who will go is not important. 2、用it作形式主语，主语从句放在句末。 It doesnt matter so much whether you will come or not. 3、that引导主语从句时，不能省略。 That he suddenly fell ill last week made us surprised. （三）表语从句 1、表语从句在复合句中作表语，位于系动词之后。 The question was who could go there. 2、引导表语从句的连接词that有时可省去。 My idea is （that） we can
24、 get more comrades to help in the work. （四）宾语从句 1、宾语从句在复合句中作宾语。引导宾语从句的连词that一般可省略。 I hope （that） everything is all right. 2、介词之后的宾语从句，不可用which或if连接，要分别用what或 whether。 Im interested in whether youve finished the work. Im interested in what youve said. 3、whether与if都可以引导宾语从句，常可互换。但下面情况不能互换。 宾语从句是否定句时，只
25、用if，不用whether。 I wonder if it doesnt rain. 用if 会引起误解，就要用whether。 Please let me know whether you want to go.（此句如果把whether改成if，容易当成条件句理解） 宾语从句中的whether 与or not直接连用，就不能换成if；不直接连用，可换。 I dont know whether or not the report is true. I dont know whether/ if the report is true or not. 介词后的宾语从句要用whether引导。wh
26、ether 可与不定式连用。whether也可引导主语从句、表语从句、同位语从句，还可引导让步状语从句，以上均不能换成if。但引导条件从句时，只能用if，而不能用whether。 It depends on whether we have enough time. They dont know whether to go there. Please come to see me if you have time. （五）同位语从句 同位语从句在句中作某一名词的同位语，一般位于该名词（如：news, fact, idea, suggestion, promise等）之后，说明该名词的具体内容。
27、I have no idea when he will be back. The fact that he had not said anything surprised everybody. 练习： 一、判断下列各句哪句含有名词性从句，并指出是什么从句： 1. China is no longer what it used to be. 2. The truth that the earth turn around the sun is known to all. 3. It was snowing when he arrived at the station. 4. How he persuaded the manager to change the plan is interesting to us all. 5. The news that they had won the game soon spread over the whole school. 6. The news that you told me yesterday was really disappointing. 7. Tha
