主語(yǔ)從句(Subject Clause)
定義
在復(fù)合句中充當(dāng)主語(yǔ)成分的句子叫做主語(yǔ)從句.
第一部分
常規(guī)主語(yǔ)從句,即句子在復(fù)合句中充當(dāng)一個(gè)主語(yǔ) 主語(yǔ)從句的時(shí)態(tài)：不受主句的時(shí)態(tài)影響和限制. （1）That he finished writing the composition in such a short time surprised us all. （2）Whether we will go for an outing tomorrow remains unknown. （3）Who will be our monitor hasn't been decided yet. （4） Whom we must study for is a question of great importance. （5）What caused the accident remains unknown. （6）Whatever you did is right. （7）Who the watch belongs to was lost is unknown. （8）What we need is time. （9）What we need are good doctors. 小結(jié): （1)引導(dǎo)主語(yǔ)從句連詞有that,whether,who,what,whatever等 （2)連詞位于句首不能省略 （3)主語(yǔ)從句大多數(shù)情況下視為第三人稱單數(shù),但也有例外,如例（9）
第二部分
為了防止句子頭重腳輕,通常把形式主語(yǔ)it放在主語(yǔ)位置,真正主語(yǔ)擱置于句末 （1）It is certain that he will win the match. （2）It is true that he has made a very important discovery in chemistry. （3）It is very likely that they will hold a meeting. （4）It is strange that he should do that. （5）It is important that we all should attend the meeting. （6）It is strange that the man should have stuck to his silly ideas. （7）It is a pity that we won't be able to go to the south to spend our summer vacation. （8）It is still a mystery what caused the accident. （9）It is said that he has gone to shanghai.(=He is said to have gone to shanghai) （10）It is known to all that the gun powder was first invented by the Chinese. （11）It is suggested that the work should be done with great care. （12）It seems that he has seen the film.(=He seems to have seen the film) （13）It happened that the two cheats were there. (=The two cheats happened to be there) 小結(jié): （1)以that 引出的主語(yǔ)從句,常以形式主語(yǔ)it引導(dǎo). It is +形容詞/名詞/某些動(dòng)詞ed + that 從句. （2) 在有些that從句中要用虛擬語(yǔ)氣 (should+do/should+have done)
主語(yǔ)從句的用法
主語(yǔ)從句與賓語(yǔ)從句兩者的用法和在句中的作用是不同的,下面從它們的各自用法來介紹. 一．主語(yǔ)從句 主語(yǔ)從句 定義:在句子中擔(dān)當(dāng)主語(yǔ)的是一個(gè)從句,這個(gè)從句就叫做主語(yǔ)從句. 主語(yǔ)從句是在復(fù)合句中充當(dāng)主語(yǔ)的從句,通常放在主句謂語(yǔ)動(dòng)詞之前或由形式主語(yǔ)it代替,而本身放在句子末尾. 1. It 作形式主語(yǔ)和it引導(dǎo)強(qiáng)調(diào)句的比較 ①主語(yǔ)從句常用it作形式主語(yǔ),一般常用句型為：It is+{名詞/形容詞/過去分詞}+主語(yǔ)從句例如： It is still a question whether she will come or not. It is strange that you should like him. It is still unknown which team will win the match. 另外,還有一些比較多見的結(jié)構(gòu)： It turned out that……； It has been proved that……; It happened/occurred that……； It is well-known that……等等 ②而強(qiáng)調(diào)句則不同,它的結(jié)構(gòu)是：It+be+被強(qiáng)調(diào)部分+that+句子的其余部分 強(qiáng)調(diào)主語(yǔ)：It is the times that produce their heroes.時(shí)勢(shì)造英雄 強(qiáng)調(diào)賓語(yǔ)：It is English that Prof.Lin teaches us. 強(qiáng)調(diào)狀語(yǔ)：It was in shanghai that I saw the film. 判斷是否是強(qiáng)調(diào)句有一個(gè)方法,就是將that以后的“句子的其余部分”拿出來單獨(dú)看,看有沒有缺成分,缺的是什么成分,再把謂語(yǔ)動(dòng)詞后面that前面的那部分,帶到你認(rèn)為缺成分的地方,如果放進(jìn)去是一句完整的句子了,那就說明是強(qiáng)調(diào)句. 2. 用it 作形式主語(yǔ)的結(jié)構(gòu) (1) It is ＋名詞＋從句 It is a fact that … 事實(shí)是… It is an honor that …非常榮幸 It is common knowledge that …是常識(shí) (2) it is ＋形容詞＋從句 It is natural that… 很自然… It is strange that… 奇怪的是… (3) it ＋不及物動(dòng)詞＋從句 It seems that… 似乎… It happened that… 碰巧… (4) it is＋過去分詞＋從句 It is reported that… 據(jù)報(bào)道… It has been proved that… 已證實(shí)… 3. 主語(yǔ)從句不可位于句首的五種情況 (1) if 引導(dǎo)的主語(yǔ)從句不可居于復(fù)合句句首. (2) It is said , (reported) …結(jié)構(gòu)中的主語(yǔ)從句不可提前.例如： It is said that President Jingo will visit our school next week. (3) It happens…, It occurs… 結(jié)構(gòu)中的主語(yǔ)從句不可提前.例如： It occurred to him that he failed in the examination. (4) It doesn’t matter how/whether …結(jié)構(gòu)中的主語(yǔ)從句不可提前.例如： It doesn’t matter whether he is wrong or not. (5) 含主語(yǔ)從句的復(fù)合句是疑問句時(shí),主語(yǔ)從句不可提前.例如： Is it likely that it will rain in the evening? 4. What 與that 在引導(dǎo)主語(yǔ)從句時(shí)的區(qū)別 What 引導(dǎo)主語(yǔ)從句時(shí)在從句中充當(dāng)句子成分,如主語(yǔ)．賓語(yǔ)．表語(yǔ),而that 則不然.例如： What you said yesterday is right. 二：賓語(yǔ)從句用以區(qū)分主語(yǔ)從句的幾個(gè)特征： 1、引導(dǎo)詞：what\which\whose\when\whether\if\where 2語(yǔ)序：賓語(yǔ)從句必須是用陳述語(yǔ)句. 如：I think that you must work harder. 賓語(yǔ)從句的引導(dǎo)詞、連接詞的區(qū)別、否定轉(zhuǎn)移等現(xiàn)象. (1)表達(dá)時(shí)間的幾個(gè)句型：一般用when或者是what time： What time will the train leave? 由于時(shí)刻都是固定的,也可以用一般現(xiàn)在時(shí)代替一般將來時(shí)： What time does the train leave? (2)時(shí)間的表達(dá)方式：8：19(nineteen past eight),7:57(three to eight),在時(shí)間的中間也可以加上分的單詞(minutes) (3)had better +動(dòng)詞原型.意思是提要求,建議.但是上下級(jí)不能用這種方式,因?yàn)檎Z(yǔ)氣太重： You had better give up smoking . (4)sb leave sth +地點(diǎn) I left my book in my classroom yesterday. (5)may I have your name(address\age)?一般詢問對(duì)方的年齡、名字等,不要習(xí)慣以前的問法,這樣很不禮貌,而是要采訪上面的問法.以前的習(xí)慣是：how old are you? \what's your name? (6)修飾名詞的代詞次序：限-描-大-形---年---顏----籍----物--------類+名詞： this is a bridge. This is a beautiful bridge 補(bǔ)充：從句的語(yǔ)序永遠(yuǎn)是陳述句.