主語從句講解46292PPT課件

1、What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe.What is even more important is that as the earth cooled down, water began to appear on its surface.What many scientists believe is that the continued presence of water allowed the

2、 earth to dissolve harmful gases and acid into the oceans and seas.表語主語賓語第1頁/共18頁1)連接代詞 what (whatever ), who ( whoever) , which (whichever), whom, whose .Which side will win is not clear. Who will write the poem has not been decided yet.Whatever he did is right.What the city will be still remains a

3、 mystery.連接代詞引導主語從句，在句中作主語，賓語，表語，定語。定語主語賓語表語第2頁/共18頁The earth became so violent that it was not clear whether the shape would last or not.It was not immediately obvious that water was to be fundamental to the development of life.So whether life will continue on the earth for millions of years to com

4、e will depend on whether this problem can be solved.第3頁/共18頁從屬連詞：that， whether 引導主語從句只起引導作用，在主語從句中不充當任何成分，that本身無實際意義，但不能省略. whether意為“是否”，放在句首句末皆可。 That price will go up is certain. That he will come is certain. Whether we go by train or by boat makes no difference. Whether hell come here isnt clea

5、r. 第4頁/共18頁Why they suddenly disappeared still remains a mystery.3)連接副詞when，where， how，why等, 在從句中做狀語。How this happened is not clear to anyone. When he will be back depends on the weather.When well start tomorrow will be told soon.Where the test will be given is not yet decided.第5頁/共18頁總結：引導主語從句的連接詞有

6、： 從屬連詞: that, whether； 連接代詞: who (whoever), whom, whose, what (whatever)和which (whichever)； 連接副詞: when, where, how和why。第6頁/共18頁Make sentences :Its certain .well be late. Is he coming or not ？We dont knowWhat does he want to tell us?We dont knowWhen will you come back?It doesnt matter.Its certain tha

7、t we will be late.That well be late is certain.We dont know whether he is coming or not .Whether he is coming is not known.We dont know what he wants to tell us.What he wants to tell us is not known.When you will come back doesnt matter.It doesnt matter when you will come back.第7頁/共18頁主語從句后置! 為了避免主語

8、冗長,句子頭重腳輕,經(jīng)常用 it 作 形式主語,主語從句放在后面作真正的主語. 例: That we shall be late is certain. - Its certain that we shall be late. 1. That the earth is round is known to all. - 2. That you missed the chance is a pity. - It is a pity that you missed the chance.Its known to all that the earth is round.第8頁/共18頁A. It +

9、be + 形容詞 + that 從句(obvious, true, surprising, good, wonderful, funny, possible, likely, certain, probable, etc.) 如：It is certain that she will do well in her exam. B. It + be + 名詞詞組 + that 從句 (an honour, a fact, a pity, etc）如：Its a pity that we cant go. 第9頁/共18頁C. It + be + 過去分詞 + that 從句 (said, rep

10、orted, thought, expected, decided, announced, etc。） 如：It is said that Mr. Green has arrived in Beijing. D. It + 不及物動詞或短語 + that 從句( seem，happen, doesnt matter ,turn out） 。如：It happened that I was out that day. It doesnt matter whether she will come or not. 第10頁/共18頁1）主語從句在句首時，必須由連接詞引導，不能省略這些連接詞。誤：Th

11、ey should like each other is natural.2)如果主語從句放在句首，不能用if引導，但是如果用it 做形式主語，而把主語從句放在句末時，也可以用if引導.誤：If Mary really heard him is really doubtful.注注 意意正： That they should like each other is natural. It is natural that they should like each other.正：Whether Mary really heard him is really doubtful. It was do

12、ubtful if Mary really heard him.第11頁/共18頁1. What you left are only several old books.2. What you said is of great importance.3）主語從句中用陳述語序4）主謂一致 主句謂語一般用單數(shù)形式。1. “what”和“who”引導主語從句時，謂語動詞的數(shù)與主句中作表語的名詞一致。How he succeeded is still a puzzle.2. 如果and 連接兩個或者兩個以上的主語從句作主語時，謂語動詞用復數(shù)；由兩個或多個連接詞引導一個主語從句時，謂語動詞用單數(shù)。Whe

13、n they will start and where they will go _ not been decided yet.When and where the meeting will be held _ not been decided.havehas第12頁/共18頁5) . 用于 It is important / natural / necessary / impossible that.句型中, 主語從句應使用虛擬語氣, 用“should + 動詞原形”的形式, should有時可以省略。6) . 在 It + be + suggested/advised/ordered/re

14、quested/ insisted/required 中, that從句的謂語也應該用“should + 動詞原形”的形式, should有時可以省略。第13頁/共18頁1.Where shall we spend the holiday isnt decided.2.You have made a mistake is a fact.3.That is certain that we can win.4.No matter who leaves the room last ought to turn off the lights.5.If the policemen will come is

15、 not certain.we shallThat you haveIt isWhoeverwhether改錯練習第14頁/共18頁6.It is say that he was a famous writer.7.It is seemed that it is going to rain soon .8.That is fact that she won the first place.9. Who leaves the room last ought to turn off the lights.10.It is important that a student learns a fore

16、ign language.said seemsIt is a factWhoevershould learn第15頁/共18頁1._ he made an important speech at the meeting was true. A. That B. Why C. What D. How 2. _well go camping tomorrow depends on the weather . A If B Whether C That D Where 3._ is known to us all that America is a developed country . A Which B As C What D It 第16頁/共18頁4. Its known to us all _ a form o