主语从句讲解

1、Subject Clauses主语从句Grammar What part does the underlined part serve as in each sentence? A tree has fallen across the road. You are a student. To find your way can be a problem. Smoking is bad for you. “How do you do? is a greeting. What she said is not yet known. That we shall be late is certain. W

2、hether he will go there is not known . How we can help the twins will be discussed at the meeting.Make sentences :Its certain that 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 wa

3、nts to tell us is not known.When you will come back doesnt matter.It doesnt matter when you will come back.主语从句后置! 为了避免主语冗长,句子头重脚轻,经常用 it 作 形式主语,主语从句放在后面作真正的主语. 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

4、the chance is a pity. - It is a pity that you missed the chance.Its known to all that the earth is round.A.It + be + 形容词 + that 从句(obvious,true,surprising,good,wonderful,funny,possible,likely,certain,probable,etc.) 如：Itiscertainthatshewilldowellinherexam.B.It + be + 名词词组 + that 从句 (anhonour,afact,ap

5、ity,etc如：Itsapitythatwecantgo.2. 用it 作形式主语的结构C.It + be + 过去分词 + that 从句 (said,reported,thought,expected,decided,announced,etc。 如：ItissaidthatMr.GreenhasarrivedinBeijing.D.It + 不及物动词或短语 + that 从句( seem，happen, doesntmatter ,turn out 。如：IthappenedthatIwasoutthatday.Itdoesntmatterwhethershewillcomeorno

6、t.1主语从句在句首时，必须由连接词引导，不能省略这些连接词。误：They should like each other is natural.2)如果主语从句放在句首，不能用if引导，但是如果用it 做形式主语，而把主语从句放在句末时，也可以用if引导.误：If Mary really heard him is really doubtful.注 意正： That they should like each other is natural. It is natural that they should like each other.正：Whether Mary really heard

7、him is really doubtful. It was doubtful if Mary really heard him.What you left are only several old books.What you said is of great importance.3主语从句中用陈述语序,后面的谓语动词用第三人称单数4“what引导主语从句时，谓语动词： 常与其后的名词作表语一致 ，且根据句子的语境而定。 eg：5) . 用于 It is important / natural / necessary / impossible that.句型中, 主语从句应使用虚拟语气,

8、用“should + 动词原形的形式, should有时可以省略。6) . 在 It + be + suggested/advised/ordered/requested/ insisted/required 中, that从句的谓语也应该用“should + 动词原形的形式, should有时可以省略。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 ro

9、om last ought to turn off the lights.5.If the policemen will come is not certain.we shallThat you haveIt isWhoeverwhether改错练习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

10、 the lights.10.It is important that a student learns a foreign language.said seemsIt is a factWhoevershould learn_ 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 4. Its known to us all _ a form of energy . A. water is B. that water is C. is water D. that wate