初中主語(yǔ)從句講解

1、主語(yǔ)從句名詞性從句包括：主語(yǔ)從句、表語(yǔ)從句、賓語(yǔ)從句和同位語(yǔ)從句。引 導(dǎo)名詞性從句的連詞有：a.連詞：that, whether, if （這三個(gè)詞都不作從句的成分，同時(shí)，that 無(wú)含義，而whether和if都表是否”）b.疑問代詞： who, whom, whose, what, whichc.疑問副詞： when, where, why, how（一）主語(yǔ)從句：在復(fù)合句中充當(dāng)主語(yǔ)的從句。l.that引導(dǎo)主語(yǔ)從句that引導(dǎo)主語(yǔ)從句時(shí)不同于其他的連詞，既無(wú)詞義也不作成分，只起 單純的連接作用，且通常不可以省。為了強(qiáng)調(diào)that引導(dǎo)的主語(yǔ)從句而 置之于句首時(shí)，that不可省。 that th

2、e driver could not control his car wasobvious. 很明顯司機(jī)不 能控制住他的車了that she was chosen made us very happy. 她被選上讓我們很高興that he will come is certain.他要來(lái)已經(jīng)千真萬(wàn)確了通常，that引導(dǎo)主語(yǔ)從句時(shí)用it做形式主語(yǔ)，把從句置于句尾，此 時(shí)that有時(shí)可省。例如： it was obvious that the driver could not control his car.彳艮明顯司機(jī)不能控制住他 it made us very happy that she w

3、as chosen.她被選上讓我 cl彳艮高興it is certain that he will come.他要來(lái)已經(jīng)千真萬(wàn)確了 如果以that從句為主語(yǔ)的句子是疑問句，就只能用先行詞 it結(jié)構(gòu)。 例如： is it certain that he will come? is it true that he would take the risk? it做形式主語(yǔ)有以下幾種不同的結(jié)構(gòu)：(1)it + be +形容詞+ that-從句 it is likely that he will come.他可能會(huì)來(lái) it is strange that she has ever trusted him

4、.她相信他，真令人奇怪 (2)it + be + 名詞 + that-從句it is common knowledge that the whale is not a fish. 鯨魚并不是魚，這 是常識(shí)its a pity that he should have catched the train.(3) it + be + -ed 分詞 + that 從句it is said that he is a famous writer.據(jù)說他是個(gè)著名作家it is reported that there will be a storm this afternoon. 據(jù)報(bào)道下午將有 一場(chǎng)暴風(fēng)在表

5、示建議、要求、命令等意義的被動(dòng)結(jié)構(gòu)中，that從句中的謂語(yǔ) 動(dòng)詞常用(should) do。(參見虛擬語(yǔ)氣部分)it is suggested that the meeting (should) be held this afternoon.會(huì)議被建議在下午舉行it is demanded that he (should) leave at once.他被要求立即離開(4) it + seem/happen/appea等不及物動(dòng)詞 + that 從句。it seems that he is wrong. 看起來(lái)似乎他錯(cuò)了it appears that they are in need of h

6、elp.看起來(lái)他們需要幫助2 . whether引導(dǎo)主語(yǔ)從句，意為 是否，只起連接作用，不充當(dāng)任何 成分。(置于句首時(shí)必須用 whether引導(dǎo)，置于句尾時(shí)，間或可用if。)whether he will win the game is not clear.他是否會(huì)贏得比賽還不清 楚。whether he will come is uncertain.他是否會(huì)來(lái)還不確定it is not clear whether/if he will come.it was uncertain whether he would come.3 .連詞代詞what, who, which, whose等引導(dǎo)的主

7、語(yǔ)從句。這些連接代詞作用相當(dāng)于代詞，在從句中擔(dān)當(dāng)主語(yǔ)、賓語(yǔ)、表語(yǔ)、定語(yǔ)等。what we need is more time.我們需要的是更多時(shí)間who was responsiblefor the accident is not yet clear.誰(shuí)應(yīng)該對(duì)這場(chǎng)事故負(fù)責(zé)還不清楚。whose book it is not important.這是誰(shuí)的書并不重要。which school you want to go matters much.你想去哪所學(xué)校很重要4 .連接副詞when, where, why, how引導(dǎo)的主語(yǔ)從句。這些連接副詞 相當(dāng)于副詞，在從句中充當(dāng)狀語(yǔ)。why he did this is not known.他為什么做這件事還不知道。when he will come is still unknown. 他什么時(shí)候來(lái)還不知道。it is not known why he did this.他為什么做這件事還不知道注意：wh-引導(dǎo)的主語(yǔ)從句也常用it作形式主語(yǔ)。5 .也可用 whatever,whoever,whomever,whenever,wherever 等詞弓 i 導(dǎo) 主語(yǔ)從句，表示 無(wú)論什么、無(wú)論誰(shuí)”、無(wú)論何時(shí)”、無(wú)論在（到） 哪里”等。whatever he