高二英语Unit5名词性从句知识精讲

高二英语Unit5名词性从句知识精讲定义：在句子中起名词作用的句子叫名词从句 (Noun Clauses）。名词从句的功能相当于名词词组,主语: His job is importantWhat he does is important.表语: This is his job.This is what he does every day.My idea is that we should help her do housework everyday.名词性从句 在复合句中能担任: 主语、宾语(介词宾语)、表语、同位语，因此,根据它在句中不同的语法功能，可分为:主语从句、宾语从句、表语从句和同位语从句。注意：1.从句一律保持陈述语序。2. 名词性从句可以表示：事实和问一、引导名词性从句的连接词可分为三类：连接连词：that, whether, if , as if ,because（不充当从句的任何成分，且that 也没有任何意义）连接代词：what, whatever, who, whoever, whom, whose, which.连接副词：when, where, how, why二、名词性从句的注意事况1、what与that 的区别：that 和 what 都可引导所有的名词从句。但是，what除起连接作用外，还在名词性从句中充当成分，表示说的、做的、想的等内容， 可做从句的主语、宾语、或表语。而that在名词性从句中不充当任何成分，只起连接作用。Eg. That he stole a bike was true. 他偷了一部自行车是真的The important thing is what you do , but not what you say .重要的是你做什么，而不是说什么。Practice:1.what he wants is a book.2. That he wants to go there is obvious.3.The result is that we won the game.4.This is what we want to know.8. I have no idea what he did that afternoon.2that不可省略的情况：a. 主语从句 、表语从句和同位语从句b.用it做形式宾语的宾语从句c.并列的宾语从句中的后几个从句的引导词that 不能省略3、whether 和 if 的区别是: （在下列情况下，whether 不能被if 取代）a. 主语从句b. 表语从句Unit4c. 同位语从句e. 介词后的宾语从句只能用“whethr”, （一般可以互换）f. whether to do 做动词宾语不能用if to do.（whether也可与动词不定式连用但if不能）g .whether or not 连在一起引导宾语从句时不用if.名词性从句作：一、主语从句：从句在句中充当主语成分，1. 通常放在主句谓语动词之前 *Eg. 1). That he will succeed is certain .2) Whether he will go there is not known .3) What he said is not true .4) Where he hid the money is to be found out .5) Whoever comes is welcome.2. 也可以由形式主语it 来代替，而将主语从句放在句末。*(1)That you didnt go to see the film is a pity.-It is a pity that you didnt go to see the film.(2) Which football team will win the match is hard to say.-It is hard to say which football team will win the match.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 “if” 不能引导主语从句，应有“whether”引导。 主语从句的 “that” 一般不能省。“what”引导主语从句时，谓语动词： 1）常与其后的名词作表语一致 2）根据句子的语境而定。1. What you left are only several old books.2. What you said is of great importance.3. What he says and does doesnt concern me.4. What he says and does dont agree.二、宾语从句：*从句在句中充当宾语成分（ 可以作谓语动词、介词、不定式等非谓语动词的宾语）连词：that, whether，if （ that 常可省略）who, what, which, whoever, whatever,when where why how（1） 主语+谓语+宾语从句*I heard (that) he joined the army. (由that 引导的宾语从句（that可以省略）)He asked how much I paid for the violin.I wonder whether you can change this note for me.She did not know what had hppened.I have no idea when he will be back.I have no idea who can finish the work.I have no idea which pen is mine.(2) 主语+谓语+间接宾语+直接宾语（宾语从句）*she told me that her mother would accecpt my invitation.Please tell me who was the first to invent the TV set.(3) 作介词宾语*He depends on what I offer.Im interested in how he got there.(4) 作某些形容词的宾语 （sure, happy, glad, certain, pleased , afraid, worried sorry , surprised等）*Im sure (that) she will like this book.Im afraid (that) Ive made a mistake.We are glad (that)so many old friends will attend our tea party.否定的转移：*若主句的谓语动词为think, consider, suppose, believe, expect,guess, imagine等其后宾语从句若含否定意义，一般 把否定词移到这些词上。Eg. I dont think this dress fits you well.注意：*1、当主句的谓语动词是一般现在时或一般将来时，宾语从句的谓语动词可以用所需要的任何一种时态。2、当主句的谓语动词是一般过去时，宾语从句的谓语动词要用相应的过去时态，但当宾语从句叙述的内容为客观真理时，仍然用一般现在时。The teacher told his class that light travels faster than sound. *1.The radio says it will be cloudy tomorrow. (be)2.The headmaster hopes everything goes well. (go)3.Tom says that they were playing (play) basketball at six oclock yesterday evening.4.I hear they have retured (return) it already.5.He said that they had been members of the Party since 1948. (be)三、 表语从句：从句在句中充当表语成分，一般放在连系动词之后. *（be,look, seem, feel,remain and so on） *作用：对主语进行解释说明。*(1)The question is whether we can rely on him.(2)Thats because we were in need of money at that time .(3)He looked as if he was going to cry .(4)Thats why I was late .注意：that 不可省， 不能用 if，只能用whether,as if /as though/because 用于表语从句1. Thats _ the Party called on us to do.A. why B. what C. how D. that2. The reason is _ he is unable to operate the machine.A. because B. why C. that D. Whether四、同位语从句：对名词作进一步解释说明，说明名词的具体内容，一般跟在一些抽象名词之后，（idea,belief, fact, truth, problem, news, question等），一般由“that”或连接副词 when / where/why / how / whether 引导.(1)I got the news that the sports meeting was put off.(2)The suggestion that Chinese students should begiven more free time is welcomed by many people.(3)The question how to tell him the truth is difficult.2. 同位语的位置：同位语有时可以不紧跟在它所说明的名词后面，而是被别的词隔开。He got the news from Mary that the sports meeting was put off.I have heard the news that he visited our factory .I have heard the news that he told you the other day .同位语从句和定语从句的区别：1 同位语从句that 只起连接作用，不作任何成分定语从句 that 是关系代词，起连接作用和充 当宾语和主语2同位语从句同位语从句和前面的名词是同位关系，对名词进行补充说明定语从句 定从和前面的名词是所属关系，对名词进行修饰，加以限定3同位语从句that 不能省定语从句 that 在从句中作宾语时，可以省1. _made the school proud was _more than 90%of the students had been admitted to key universities .A What / because B What / that