whether和if在宾语从句中的区别！
(1)whether和if在宾语从句中可以互换，但是从句作介词的宾语时连接词一般只能用whether。如:
It all depends on whether they will come back.
not,，但whether可直接与or not连用。如:
(2)两者后面都可加or not,但whether后可直接与or not连用。如：
I didn't know whether/if he had arrived in Wuhan or not.
I wonder whether or not we should make it clear that we've lost this game.
(3 )if/whether引导主语从句时，whether引导的主语从句可置于句首，但if引导的主语从句不能置于句首，只能放于句末。引导表语从句一般只能用whether。如:
Whether the meeting will be put off has not been decided yet.
The question is whether they have so much money.
(4) whether可以引导同位语从句,用以解释说明前面的名词的内容,但if不能。如:
We ought to discuss carefully the question whether we can do it or not.
(5)whether可与动词不定式连用,但if不能。如:
I have not decided whether to go.
2．whether和if的区别： 引导动词后面的宾语从句时，一般情况下二者可以通用；引导形容词后面的宾语从句时，二者可以通用（如： He is not sure whether/if it is right or wrong.）。但是以下 几种情况只能使用whether而不能使用if： A）引导主语从句时： Whetherwe shall attend the meeting hasn’t been decided yet.注意： 如果使用it作形式主语，则whether和if都能引导主语从句。如： It hasn’t been decidedwhether/ifwe shall attend the meeting. B)引导表语从句时： The question iswhetherthe film is worth seeing. C)引导同位语从句时： D）引导动词后面的宾语从句置于句首时： Whethershe is married I don’t kn ow.E)引导动词后面的宾语从句表示选择概念时： 1) He wonderedwhetherhe should wait for them or go on. 2) He wonderedwhetherhe should go there by air or by sea. F）引导动词后的宾语从句，后面紧接or not时： 当or not置于句末时，也可使用if。如： They discussedwhetherJohn could attend the meeting.H)引导介词后面的宾语从句时：
It all depends onwhetherthey will support us. I)后接动词不定式作宾语时： He doesn’t knowwhetherto stay (or not). J)为了避免与表示条件的if重复或为了避免产生歧义时，常使用whether： 1) He askedwhether, if I got the job, I’d move to Beijing. 2) Please let me knowifyou like it.该句可译为“请告诉我你是否喜欢。”或“如果你喜欢，请告诉我。”如果使用whether就可以避免产生歧义。 注意： whether可以引导让步状语从句，意为“不论是否…，不管是…还是…”。例如： WhetherI am busyor not, I shall spare no effort to learn English well. 3.疑问词与关系词的区别: A)疑问词引导的名词性从句含有疑问意义；关系词引导的名词性从句不含有疑问意义，相当于一个名词或代词后加一个定语从句。注意以下关系词引导的名词性从句： 1) What he said proved to be right.他所说的后来证明是对的。 2）He is no longer what he was five years ago.他已不再是五年前的样子了。 3）The morning is when I’m busiest.早上是我最忙的时候。 4) This is where I disagree.这一点是我所不同意的。 5) The coat is where you left it.大衣还在你原来放的地方。 6) That’s how I look at it.这是我对这个问题的看法。 7) That’s why I object to the plan.这就是我反对这个计划的原因。
从句小结 从句总述： 从句有主语从句、表语从句、宾语从句、同位语从句、定语从句和状语从句6类。 由于主语从句、表语从句、宾语从句及同位语从句在句子的功用相当于名词，故而这4种从句又通称名词性从句。 1.主语从句（Subject Clause）：用作主语的从句叫主语从句。引导主语从句的关联词有从属连词、疑问代词、疑问副词、缩合连接代词、缩合连接副词等。 2.表语从句（Predicative Clause）：用作表语的从句叫表语从句。引导表语从句的关联词与引导主语从句的关联词大都一样。 3.宾语从句（Object Clause）：在句子中起宾语作用的从句叫做宾语从句.宾语从句分为三类:动词的宾语从句,介词的宾语从句和形容词的宾语从句. 4. 同位语从句（Appositive Clause）：在复合句中用作同位语的从句叫同位语从句。它一般跟在某些名词后面，用以说明该名词表示的具体内容。其关联词多为that。 状语从句还可以分为条件状语从句、原因状语从句、方位状语从句和时间状语从句等。 宾语从句 学习宾语从句要抓住三要素：时态、语序、连接词。 一：时态和语序 1·主句用一般现在时，从句可用任意时态。 2·主句用过去时，从句用过去某个时态。 3·主句用过去时，从句是真理时，只用一般现在时。 语序：宾语从句只能用陈述句语序，坚决不能用疑问句语序。 二：连接词 ①从属连词 连接宾语从句的从属连词主要有that，if，whether. that引导表示陈述句的宾语从句,而if和whether引导表示“是否”的宾语从句. 例句： He told that he would go to the college the next year 他告诉我他下一年上大学. I don’t know if there will be a bus any more. 我不知道是否还会有公交车. ②连接代词 连接代词主要有who, whom ,whose ,what ,whoever ,whomever ,whosever, whatever, whichever等. 连接代词一般指疑问,但what, whatever除了指疑问外,也可以指陈述. 例句： Do you know who has won Red Alert game 你知道谁赢了这一局红警游戏吗 ③连接副词 连接副词主要有when,where,why,how,whenever,wherever,however等. 例句： He didn’t tell me when we should meet again. 他没有告诉我什么时候我们能再见面.
If引导的条件状语从句 [课本链接] If you do, you’ll be sorry. (Unit 5, Section A) [定义] 条件状语从句通常由if（如果），unless（除非），as long as（只要）引导。 if引导的条件状语从句表示假如从句的动作发生，主句的动作就（不）会发生。[句子结构] 中考考点之[时态呼应] 在复合句中： ⑴当主句是一般现在时或是一般将来时时； （2）当主句是祈使句时； （3）当主句含有情态动词时，if引导的条件状语从句通常用一般现在时。如：
例句： If she doesn’t come, she will be sorry. 如果她不来，她会遗憾的。 Have a good rest if you are tired. 如果累了，你就好好休息一下。 We must study hard if we want to pass the final exam. 如果想通过期末考试，我们必须努力学习。 [同义句转换] 1. If引导的条件状语从句可以用“祈使句，＋and / or ＋一般将来时的句子”转换。 祈使句,+and+陈述句可以转化为if 引导的肯定条件状语从句。 祈使句,+or+陈述句可以转化为if 引导的否定条件状语从句。如： If you work hard, you’ll pass the exam easily. → Work hard, and you’ll pass the exam easily. 努力学习，你将很容易通过考试。 If you don’t hurry up, you’ll miss the train. → Hurry up, or you’ll miss the train. 快点儿，否则你就赶不上火车了。 真题(2010重庆中考)Work hard，________ you may catch up with your classmates soon. A.or B.but C.and D.yet 课后练习：用if连接下列句子 1、Go to bed early，and you will have a good rest. 2、Hurry up, or you’ll miss the bus. 2. 用含介词with或without的介词短语转换。如： If there is no water, fish can’t live. → Fish can’t live without water. 离开水，鱼不能生存。 [if引导的条件状语从句和宾语从句的区别]
Ⅰ.用适当的连接词填空 1．The trouble is that I can’t find my way. 2．We are discussing what we shall do to help the poor. 3．It depends on whether you can do the work well. 4．I wonder how you are getting on with your studies. 5．He got caught in the heavy traffic.That was why he was late. 6．Energy is what makes things work. 7．We didn’t set out; it was because we wanted to wait until our mother came back. 8．We consider it necessary that he should improve his pronunciation. Ⅱ.单项填空 1．—Can you join us in the party this evening? —Well, that depends on ________ I can finish my report before then. A．whether B．if C．that D．when 解析：选A。句意：“你今天晚上能参加我们的聚会吗？”“嗯，那得看到时候我的报 告能不能完成。”连词whether表示“是否”，引导宾语从句。if表示“是否”，不引导介词的宾语从句；that没有意义；when“当……时”。 2．I don’t think ________ possible ________ one can master a foreign language without much memory work. A．it; whether B．it; that C．which; whether D．this; that 解析：选B。it在句中作形式宾语；possible作宾补；真正的宾语是that引导的宾语从句。 3．He said________he had eaten nothing for a long time and________he was very hungry. A．that; 不填B．不填；that C．不填；不填D．what; what 解析：选B。考查宾语从句中that的省略问题。said后接了两个that引导的宾语从句，其中第一个从句中的that可省略，后面的that不可省略。 4．The reason for his coming to China was ________ he wanted to study Chinese medicine. A．that B．what
10级A班第六组作业 同位语从句 一、同位语从句的概念在复合句中用作名词的从句叫同位语从句, 其主要用途就是对前面的名词做进一步解释说明该名词的具体内容。 可以跟同位语从句的名词通常就 是: news,fact,promise,question,doubt,thought,hope,message ,suggestion,word, possibility,order,fear,proof,belief,advise,demand,problem,request,truth,wish 例句: I just got word that he is not coming this evening 、 Wehaven 't yet settled the question where we are going to spend our summervacation 、The Mona Lisa is widely seen as proof that good looks can last for ever There is no doubt that he is guilty 、 There is great doubt whether he did so or not 、 二.同位语从句的先行词同位语从句的先行词通常就是抽象名词, 常见的有:idea, situation thought, fact, evidence, belief, doubt, fear, hope, question, theory, news, order, ability 例句: 等等。How did the cheats explain the fact that the Emperor didn't feel the new clothes in him? 皇帝觉得身上并没有穿上新衣, 对这个问题骗子就是怎样解释的? The news that his heath is failing made us sad 、 她健康状况不佳的消息使我们很难过。 I have no idea where they are spending their holidays 、我不知道她们在哪里度假。 The question who should do the work requires consideration 、谁该干这项工作的问题需要考虑 There is no doubt that he will come here again 、她会再来这里, 这就是毫无疑问的。He was tortured by the doubt whether he would accept their presents 、她被就是否接受她们的礼物这个疑虑所折磨着。 三.同位语从句的引导词 1、连词that 引导同位语从句 The idea that you can do this work well without thinking is quite wrong 、您认为不动脑筋就能做好这件工作的想法就是完全错误的。（作idea的同位语） He gabbed his suitcase and gave the impression he was boarding the Tokyo plane 她拿起了手提箱, 给人的印象就是她要登上飞往东京的飞机了。 以下名词常用于以上句型: advice, announcement, argument, belief, claim, conclusion, decision, evidence, explanation, fact, feeling, hope, idea, impression, information, knowledge, message, news, opinion, order, probability, promise, proposal, remark, reply, report, saying, statement, suggestion, thought, treat, warning, wish, word
1．在句中担当宾语的从句叫宾语从句，宾语从句可作谓语动词的宾语，也可做介词的宾语。 eg, He said he was good at drawing. (动词宾语) He asks him how long Mike has been down . (动词宾语) Miss Zhang is angry at what you said. (介词宾语) 2．宾语从句的引导词有三类： (1) 以that 引导的宾语从句，主要用来引导句形式的宾语从句，that可以省略。eg, The radio says (that) the clouds will lift later on. She told me (that) she would like to go with us. (2) 以连接代词which, what, who等或连接副词how, where, why 等引导的宾语从句，从句是陈述语序 eg, Could you tell me what's the matter with u? I want to know how soon it will begin. (3) 以whether 或if 引导的宾语从句, 主要用来引导一般疑问句意思或选择疑问句意思的宾语从句，从句同样是陈述语序 eg, I wonder if /whether u have told the new to Li Lei . 3．宾语从句的时态 (1) 当主句为一般现在时态、现在进行时态、或一般将来时态时，从句可用所需要的任何时态。 eg, I want to know what time he got up this morning. You are telling me that you won't stop until tomorrow? (2) 当主句为一般过去时态时，从句要用于过去有关的时态。 eg,They asked what Jean was doing now . Linda said that the train had left. (3) 当从句表述的是客观真理或自然现象时，宾语从句要使用一般现在时。 eg, Lisa asked whether light travels faster than sound. Polly said no news is a good news 注意：一般情况下， W h e t h e r和if 可以互用,但有些情况例外。 1. 当从句做介词的宾于是只用whether 不用I t eg, We are talking about whether we'll go on the pinic. 2. 引导词与动词不定式或not 连用时，只用w h e t h e r. eg, Please let me know what to do next. Could you tell me whether u go or not? 3. if当如果讲时，引导的是条件状语从句，这时不能用whether. e,g, You can't work the plan out if you don't have the meeting .
宾语从句和表语从句详解 名词性从句指的是在整个句子中起名词作用的从句。这种从句可以做主语、宾语、表语、同位语等，所以这类从句包括主语从句、宾语从句、表语从句和同位语从句。各种名词性从句的结构都是相同的，即由if，whether，that和各种疑问词充当连接词，后接陈述语序。 例如：What they are doing seems very important．（主语从句） 他们在做的事似乎很重要。 My hope is that he will be the best student in the class．（表语从句） 我的愿望是他能够成为班上最好的学生。 Nobody knows who he is．（宾语从句） 大家都不知道他是谁。 I don't like the idea that money is everything．（同位语从句） 我不喜欢金钱就是一切这一观点。 引导名词性从句的连接词中，除了that，if和whether之外其它的都作从句中的一个成分。 【宾语从句】 在句子中作动词或介词宾语的从句叫做宾语从句。引导宾语从句的词有连词that，whether，if；连接代词who，which，what以及其强调形式whoever，whichever，whatever；连接副词when，where，why，how等。 例如：Do you know where the Greens live I have no interest in how rich he is． 宾语从句主要用于下面五种结构： 1．由that引导的宾语从句（that 引导宾语从句时，特别是在口语中可省略） The boy believes that he will travel through space to other planets． that引导的宾语从句多用于say，think，insist，wish，hope，demand，imagine，wonder，know，suppose，see，believe，agree，admit，deny，expect，explain，order，command，feel，dream，suggest，hear，mean，notice，prefer，request，require，propose，declare，report等后。 当主句谓语动词是think，believe，suppose，expect 等词，而宾语从句的意思是否定时，常把否定转移至主句表示。例如：I don’t think it is right for him to treat you like that．（＝I think it is not right for him …．） that不能省略的情况： （1）当句中的动词后接多于两个由that引导的宾语从句时，第一个that可省，但后面的that不可省。如： He said （that）you were too young to understand the matter and that he was asked not to tell you． （2）当主句的谓语动词与that宾语从句之间有插入语时，that一般不可省。如： Just then I noticed，for the first time，that our master was wearing his fine green coat and his black silk cap． （3）当that从句是双宾语中的直接宾语时，that不可省。如： I can’t tell him that his mother died． 2．由特殊疑问词引导的宾语从句 这样的宾语从句实际上是由特殊疑问句变化而来的，宾语从句要用陈述句语序。用于这种结构的动词常常是：see，say，tell，ask，answer，know，decide，show，find out，imagine，suggest，doubt，wonder，discover，understand，inform，advise等。
If 引导的条件，虚拟和宾语从句 1.If you _____ to the party, you’ll have a great time . A. will go B. went C. go D. going 2 I ____ her the answer if she ____me. A.can tell, will ask B. will tell, will ask C. would tell, ask D. will tell, asks 3. – What are you going to do tomorrow? --We’ll go to the library tomorrow if it ___. A.isn’t rain B. rain C. won’t rain D. doesn’t rain 4.—Do you know when he will come back tomorrow? --Sorry, I don’t know. When he ____ back, I’ll tell you. https://www.doczj.com/doc/e53678146.html,es B. will come C. come D. may come 6 7 8 9 10.---Tommy ,do you know if Frank _______ to the zoo this Sunday if it _____? --- Sorry ,I have no idea. A.goes, will rain B. Will go , rains C. Would go, rain D. Went, would rain 11.---Mike ,could you tell me if Mary _____________ to my party tomorrow? ---I think she will if she _________ time. A come, has B comes, will have C will come ,has D will come, will have 12.I don't know if I _______ anyone at the party this evening .If I ______ anyone, I will get nervous . A will know, won't know B will know ,didn't know C know, won't know D know, don't know
主语从句与宾语从句 一、名词性从句是四位从句的总称：主语从句、宾语从句、同位语从句、表语从句。这些从句都起到类似于名词的作用。 主从：一个句子充当大句子的主语，就叫主语从句。例如； What I need is money.(主语是What I need作大句的主语) It was not obvious that water is fundamental to the development of life.（It是形式主语，真正的主语是that 从句。） 主语从句的位置有两种，一种是放于句首；一种是用It 作形式主语，从句被放后面。 二、宾语从句：一个小句子充当大句子的宾语。 He asked me how old I was . She took it for granted that I’d be back home an hour ago.（It 作形式宾语，真正的宾语是后面的that从句。） 考点一：语序 What I want to do is to go home immediately.陈述语序。 I asked where the famous restaurant was .陈述语序。 名词性从句的语序应该是陈述句语序。 删除疑问语序（be /助动词、情态动词+主语） 考点二：引导词 That（没成分） That the earth moves around the sun is known to all.(that 引导的句子作大句子的主语，that不能丢。) Whether /if （有时互换，主语从句只能用wheather引导，不能用if .可用if 的地方都能用wheather。） Whether the meeting will be put off depends on the weather . 疑问代词：what,who, whom,which,whose 在从句中有成分 What he has is just money.（在从句中有成分作宾语） 疑问副词：where ,when,why,,how在从句中有成分 Why he didn’t attend class is not know yet. That：引导名词性从句时无成分，无词义，有时可以省略。 Whether /if引导名词性从句时无成分，是否。 特殊疑问代词：主，宾，表，定。 疑问副词：状。 考点三：no matter+疑问词（what）VS疑问词（what）+ever Whatever he says must be put down . No matter what he says/Whatever he says,I will not change my mind. 意思相同，但语法不一样。第一句主从，第二句让步状语从句。以ever开头的引导主从或者状语从句，而以no matter 开头的不能引导名词性从句，只能引导状语从句，所以选ever 就一定对。 考点四：建议、命令、要求类+宾从 The doctor suggested that an operation (should)be done immediately on the patient. 初中讲过当主句是一般过去时态的宾语从句：主过去，从句也过去。当主句的动词是建议、命令、要求类的动词时，后面的宾从必须是should+动词原形且should可以省略。此时不管。主语是谁，不管主句是什么时态都不能改变动词是原形的要求.once表示建议、命令、要求类的动词suggest,advise,propose,demand,require,insist,request,ask,command,order后面如果后
Grammar—appositive clauses＆predicative clauses 名词性从句之同位语＆表语从句 同位语从句： I.明确概念与特征： 1. 同位语从句常放在名词之后，用来补充说明名词的具体内容。常用来接同位语从句的名词有news, idea, promise, question, doubt, wonder, fact, hope, wish, suggestion, advice, possibility, message, word, belief, information等。常用来引导同位语从句的连词有that, what, who, whether以及连接副词where, when, why, how 等。如： The news that their children couldn’t come back on time worried all the parents. I had no idea when the storm would end. 2. 不过有时候为了保持句子结构平衡，同位语从句也不一定直接放在名词后，而会出现隔离情况。如： Word came that the sports meet had been put off. Suddenly a good idea occurred to me that I could buy my teacher a gift. 3. 同位语从句前名词的数 同位语从句前的名词通常用单数形式，并且往往带有限定词加以修饰。如：Where did you get the idea that I could not come? Give me your promise that you will come to our party this evening. Exciting word came that I passed the exam. II. 正确选用引导词 一般来说根据句意来确定相应的引导词，并且从句要用陈述句的语序。 1.that引导同位语从句时在句中不作任何成分，但不可省略； The idea that we play football after class is great. 2.在表示是否的意思时连词只能用whether而不能用if； The question whether you can go to an ideal university depends on your effort. 3.从句若缺少主语,宾语或定语用连接代词（what, who, whom, whose, which），若缺少状语用连接副词（when, where, how, why）引导。 I have no idea which mobile phone is the best—it’s a matter of personal taste. At last I made a decision that I would never come back again. The question what we should do with this situation is under discussion. All of us had no idea why he refused our help. The question why he didn’t attend the meeting puzzled us. We can’t solve the problem how we can travel faster than light. 4.在名词doubt“怀疑”后的同位语从句用whether连接；在no doubt“不怀疑”之后的同位语从句用that连接。例如： There is no doubt that we will win the final match. I have a doubt whether he will finish the job on time. III. 注意从句中的时态 一般来说同位语从句的时态要和主句的时态保持一致。但在表示请求、命令、建议等意思的名词后的同位语从句中的谓语动词应用(should) do，(如demand, wish, suggestion, advice，order等)后面的同位语从句要用虚拟语气。如 I have no idea when he will be back. I accepted my father’s advice that I (should) apologize to my friend.
年级初二学科英语版本外研社（新标准）课程标题If引导的从句 编稿老师李晶 一校林卉二校黄楠审核刘晓军 一、学习目标 1. 掌握if引导的宾语从句的用法。 2. 掌握if引导的条件状语从句的用法。 3. 能恰当使用含有if引导的条件状语从句的复合句中主从句的时态。 二、重点、难点 1. 含有if引导的条件状语从句的复合句中主从句的时态。 2. If引导的宾语从句与条件状语从句的区别。 三、考情分析 通常在单项选择、完形填空或补全、完成句子等题型中考查，分值约3—4分。 四、知能提升 （一）知识讲解 【认知讲解】 I. if引导的宾语从句 if 引导宾语从句时，意思为：是否，从句的时态通常要和主句保持一致。 【例句】 I want to know if he lives there. 我想知道他是否住在那儿。 He asked me if I could help him. 他问我是否能帮他。 【考查点】if、whether引导的宾语从句的区别 1. if或whether引导宾语从句时，作“是否”讲，常放在动词ask、see、say、know和find out等后面。一般情况下，两者常可换用，在口语中多用if。 【例句】 Nobody knows whether / if it will rain tomorrow. 没有人知道明天是否下雨。 Lucy asked whether / if they had a cotton sweater. 露西问他们是否有棉制的毛衣。 2. if或whether引导宾语从句时，要注意三个方面，即连词、语序和时态。 if或whether既不能和that 或其他连词（副词）同时使用，也不能省略。 【例句】 我不知道他今天是否会来。 [误] I don’t know that if(whether) he will come here today. [正] I don’t know if(whether) he will come here today.
名词性从句 名词性从句（主语、表语、宾语、同位语从句） （一）主语从句 1．定义：用作主语的从句叫做主语从句。 2．构成：关联词+简单句 3．引导主语从句的关联词有三类： (1) 从属连词that。如： That they were in truth sisters was clear from the facial resemblance between them. 很明显，她们确是亲姐妹，她们的脸型很相似。 (2) 从属连词whether。如： Whether he’ll come here isn’t clear. 他是否会来这里还不清楚。 (3) 连接代词who, whom, whose, what, which, whoever, whatever, whichever 连接副词where, when, how, why。如： What she did is not yet known. 她干了什么尚不清楚。 解释： 1．主语从句能用it作形式上的主语。常以it作形式主语的句型有： A. It+be+形容词(obvious, true, natural, surprising, good, wonderful, funny, possible, likely, certain, probable, etc.)+that从句。如： It is certain that she will do well in her exam. 毫无疑问她考试成绩会很好。 B. It+be+名词词组(no wonder, an honour, a good thing, a pity, no surprise, etc.)+that从句。如：It’s a pity that we can’t go. 很遗憾我们不能去。。 C.It+seem, happen等不及物动词及短语+that从句。如： It seems that Alice is not coming to the party at all. Alice似乎不来参加晚会。 D.It+doesn’t matter (makes no difference, etc.)+连接代词或连接副词引起的主语从句。如： It doesn’t matter whether she will come or not. 她是否来这无关紧要。 F. 当that引导的主语从句出现在疑问句中时，要以it作形式主语，而把主语从句后置。如：Does it matter much that they will not come tomorrow? 他们明天不来很要紧吗？ G. 当主语从句出现在感叹句中时，要以it作形式主语，而把主语从句后置。如： How strange it is that the children are so quiet! 孩子们这么安静真奇怪！ 2．注意连接代词whoever, whatever, whichever等引导主语从句的含义 Whoever comes will be welcome. (whoever=the person who) 来的人将受到欢迎。 （二）表语从句 1．定义：用作表语的从句叫做表语从句。 2．构成：关联词+简单句 3．引导表语从句的关联词的种类： (1) 从属连词that。如： The trouble is that I have lost his address. 麻烦是我把他的地址丢了。
that, whether / if引导的宾语从句 在复合句中，由一个句子充当宾语，这个句子叫作宾语从句。我们需要从三方面来学习由that, whether / if引导的宾语从句。 一、关联词 1.陈述句作宾语时，宾语从句用that引导。that只起连接作用，没有实际意义，在从句中不充当任何成分，因此常省略。如： He can visit Beijing one day. My brother hopes. (合并为含有宾语从句的复合句)My brother hopes (that) he can visit Beijing one day. 2.一般疑问句作宾语时，宾语从句用whether或if引导。whether和if意为“是否”，在从句中不充当任何成分，但不可省略。如： Is Tom's sister an English teacher? May wants to know.(合并为含有宾语从句的复合句) May wants to know whether / if Tom's sister is an English teacher. 二、语序 that, whether / if引导的宾语从句要用陈述句语序。如： Will she go to Beijing tomorrow? I don't know.(合并为含有宾语从句的复合句)I don't know whether / if she will go to Beijing tomorrow. 三、时态 1.如果主句是一般现在时，that, whether / if引导的宾语从句可根据需要使用适当的时态；如果主句是一般过去时，that, whether / if引导的宾语从句用相应的过去时态(一般现在时→一般过去时，现在进行时→过去进行时，一般将来时→过去将来时，现在完成时→过去完成时，一般过去时→过去完成时)。如：Andy knows (that) his wife bought a nice dress yesterday. I want to know whether / if my father will go to London next week.
怎么区分定从宾从同位语从句？（从成分方面） 老师说什么。。。做在句子中做成分就是。。。去掉以后句子不完整就是。。。。 满意答案： 从句按其在主句中的句法功能可分为三类，即名词性从句、形容词性从句(即定语从句)和副词性从句(即状语从句)。引导从句的词称作关联句。名词性从句包括主语从句、表语从句、宾语从句和同位语从句。引导这些名词性从句的关联词包括: 从属连词that, if, whether; 连接代词who, whoever, whom, whomever, which, whichever, what, whatever, whose; 连接副词where, when, why, how。其中, 从属连词只起连接作用, 在从句中不充当任何句法成分,而连接代词和连接副词既起连接作用, 在从句中又充当一定的成分. That Owen should have married his cousin is not at all surprising. The fact is that he didn't go to the dinner party. I don't know if he will attend the meeting. Have you heard the news that Mary is going to marry Tom? 你听说玛丽要和汤姆结婚的消息了吗?(that引导同位语从句) [提示] 1. 在含有主语从句的复合句中, 为保持句子平衡, 常用it作形式主语,而将真正的主语从句置于句末. It's well known that water is indispensable to life. 2. 为保持句子平衡, that引导的宾语从句也常用it代替, 而将真正的宾语从句置于主句句末。这常常出现在主句有形容词或分词作宾语补足语的情况下。He made it quite clear that he preferred to live here. 3. 从属连词whether和if都作“是否…”解, 但if不可引导主语从句和表语从句。whether可与or(not)连用, 而if不可以。I don't know whether (if) she is at home. Whether she comes or not makes no difference. 4. that和what引导名词性从句的区别: that在从句中不充当成分,而what在从句中充当一定的成分, 如主语、表语、宾语等。that可省略, what则不可省。He always means what he says. She suggested (that) he do it at once. 5. 同位语从句大多由从属连词that引导, 常跟在下列名词后面,如fact, idea, opinion, news, hope, belief等, that不可省，一般用来解释说明这些名词的具体含义和内容。We are familiar with the idea that all matter consists of atoms. The news that we are invited to the conference is very encouraging. 如何判断各类从句呢？答：1．分析句子结构以区分从句的种类。遇到一个复合句，首先要分析其句子结构，看从句在整个句子中起什么作用，那么它就是什么从句。2．分析引导词的句法作用以区别从句的种类。that这个词既可引导同位语从句，又可引导定语从句，这种两种从句从形式和结构上看特别相似，如何区分呢？区分that引导的是同位语从句还是定语从句的方法是，看that在从句中是否充当句子成分，若that在从句中不充当任何成分，则为同位语从句；若that在从句中充当主语或宾语，则为定语从句。3．根据被修饰词来判断从句的种类。定语从句常常修饰一些具有实际意义的名词，如：the film；the student；the book；a house等等。而同位语从句常常修饰一些表示抽象概念的名词，如fact、idea、promise、truth等，用来说明这些名词所表示的具体内容。状语从句在句子中常用来修饰谓语动词。4．根据从句前词的词性来判断从句的种类。宾语从句分两种：动词的宾语从句、介词的宾语从句。宾语从句前肯定是动词或介词。定语从句是用来修饰名词或代词的，所以其前一定是一个名词或代词。5．根据上下文意义和结构形式上区分从句的种类。如so that即可引导目的状语从句，又可引导结果状语从句，如何区分呢？主要从以下两点来区分。①根据上下文意义判断。“以便……”表示目的，是目的状语从句，“以致于……”，“结果……”表示结果，是结果状语从句。②从结构形式上来分辨。so that前有逗号，为结勤劳的蜜蜂有糖吃 果状语从句，反之，则为目的状语从句。有时，so that前无逗号，这里要看从句中有无can、could、may、might、will、would、should 等情态动词，如果有，则多是目的状语从句，若没有，则多是结果状语从句。