主語(yǔ)從句講解

1、 1 / 5 主語(yǔ)從句講解 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.引導(dǎo)主語(yǔ)從句的關(guān)聯(lián)詞有三類： (1)從屬連詞that，whether That they were true sisters was clear from the facial resemblance between them.Whether he'll come here isn't clear. (2)連接代詞who, whom, whose, what, wh

2、ich, whoever, whatever, whichever，What she did is not yet known. How this happened is not clear to anyone. Whoever comes is welcome. (3)連接副詞where，when, how, why 2.主語(yǔ)從句是在復(fù)合句中充當(dāng)主語(yǔ)的從句，其功同名詞一樣。為了避免頭重腳輕，常用it作形式主語(yǔ),而把真正主語(yǔ)放在句子末尾。 How the book will sell depends on its author. That he is the best student in t

3、he class is obvious. = It is obvious that he is the best student in the class. 注意：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。 2 / 5 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 t

4、hat 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(wèn)句時(shí)，主語(yǔ)從句不可提前。 例如：Is it likely that it will rain in the evening? 3.主語(yǔ)從句用陳述語(yǔ)序。關(guān)聯(lián)詞位于句首不能省略。 How he became a great scientist is known to us all. That h

5、e finished writing the composition in such a short time surprised us all. 4.主語(yǔ)從句中注意的事項(xiàng)： 1）在主語(yǔ)從句中，謂語(yǔ)動(dòng)詞一般用單數(shù)。 Whatever he says is of no importance. Whoever says this is wrong. 但謂語(yǔ)動(dòng)詞用單數(shù)還是復(fù)數(shù)，不可一概而論，而要視句子的意義而定 What I need is money. What I need are books. 2）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

6、語(yǔ)、表語(yǔ)，而that則不然。 What you said yesterday is right. 3 / 5 That she is still alive is a consolation. 3）It作形式主語(yǔ)和it引導(dǎo)強(qiáng)調(diào)句的比較 It作形式主語(yǔ)代替主語(yǔ)從句，主要是為了平衡句子結(jié)構(gòu)，主語(yǔ)從句的連接詞沒(méi)有變化。而it引導(dǎo)的強(qiáng)調(diào)句則是對(duì)句子某一部分進(jìn)行強(qiáng)調(diào)，無(wú)論強(qiáng)調(diào)的是什么成分，都可用連詞that。被強(qiáng)調(diào)部分指人是也可用who/whom。 1. It作形式主語(yǔ)和it引導(dǎo)強(qiáng)調(diào)句的比較 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(guò)去分詞+主語(yǔ)從句例如： It is st

7、ill 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. 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+從句 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 s

8、aw 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(lái)單獨(dú)看，看有沒(méi)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(shuō)明是強(qiáng)調(diào)句。 It is still a mystery what caused the accident. It is a mystery that his death remained. 4) whether與if 4 / 5 whether引導(dǎo)主語(yǔ)從句時(shí),常置于句首(此時(shí)whether不能用if代替),也有后移的用法(此時(shí)whether可以用if代替) W

9、hether they will come is not yet known. It is not yet known whether / if they will go there. whether和if的區(qū)別還有： 1.引導(dǎo)表語(yǔ)從句用whether The question is whether you should accept it. 2. whether可以引導(dǎo)從句作介詞的賓語(yǔ) I'm not interested in whether they'll go or not. It depends on whether we have got enough money. 3. whether可以直接跟動(dòng)詞不定式連用 I didn't know whether to laugh or to cry. She hasn't decided whether to go or not. 5）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