主语从句讲解

5. It worried her a bit ___ her hair was turning gray. A. whether B. that C. what D. when
6.What I say and think ___ none of your business. A. is B. are C. has D have
3.___ is known to us all that America is a developed country . A Which B As C What D It
ห้องสมุดไป่ตู้
4. It’s known to us all ___ a form of energy .
A. water is C. is water B. that water is D. that water to
Make sentences :
It’s certain . we’ll be late. Is he coming or not ？
It’s certain that we will be late. That we’ll be late is certain. We don’t know whether he is coming or not . Whether he is coming is not known. What does he want to We don’t know what he wants to tell us. tell us? What he wants to tell us is not known. We don’t know When will you come back? It doesn’t matter. It doesn’t matter when you will come back. When you will come back doesn’t matter.
1.连接词：
1）从属连词：that， whether 引导主语从句只起引 导作用，在主语从句中不充当任何成分，that本身 无实际意义，但不能省略. whether意为“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 he’ll come here isn’t clear.
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.
动词原形”的形式, should有时可以省略。
改错练习
1.Where shall we spend the holiday isn’t decided. we shall 2.You have made a mistake is a fact. That you have
3.That is certain that we can win.
-- It’s known to all that the earth is round.
2. That you missed the chance is a pity. -- It is a pity that you missed the chance.
2. 用it 作形式主语的结构
A. It + be + 形容词 + that 从句 (obvious, true, surprising, good, wonderful, funny, possib le, likely, certain, probable, etc.) 如：
1. ___ he made an important speech at the meeting was true.
A. That B. Why C. What D. How
2. ___we’ll go camping tomorrow depends on the weather . A If B Whether C That D Where
It is certain that she will do well in her exam. B. It + be + 名词词组 + that 从句 (an honour, a fact, a pity, etc）如： It’s a pity that we can’t go.
C. It + be + 过去分词 + that 从句 (said, reported, thought, expected, decided, announced, etc。） 如：
2)连接代词 who ( whoever) , what
(whatever ), 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. Who killed the scientist remains a question. Whom she borrowed money from still puzzled him.
It is 4.No matter who leaves the room last ought to turn off the lights. Whoever 5.If the policemen will come is not certain. whether
6.It is say that he was a famous writer. said 7.It is seemed that it is going to rain soon . seems 8.That is fact that she won the first place. It is a fact 9. Who leaves the room last ought to turn off the lights. Whoever 10.It is important that a student learns a foreign language. should learn
5) . 用于 It is important / natural / necessary / impossible that...句型中, 主语从句应使用虚拟语气, 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 +
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： 1. What you left are only several old books.
2. What you said is of great importance.
It doesn’t matter whether she will come or not.
注 意
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. 正： That they should like each other is natural. It is natural that they should like each other. 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. 正：Whether Mary really heard him is really doubtful. It was doubtful if Mary really heard him.
定义： 用作主语的从句叫主语从句，它是名词 性从句之一。 引导主语从句的连接词有： 从属连词: that, whether； 连接代词: who (whoever), whom, whose, what (whatever)和which (whichever)； 连接副词: when, where, how和why。
“How do you do?” is a greeting.
What she said is not yet known.
That we shall be late is certain.
Whether he will go there is not known . How we can help the twins will be discussed at the meeting.
It is said that Mr. Green has arrived in Beijing.
D. It + 不及物动词或短语 + that 从句 ( seem，happen, doesn’t matter ,turn out） 。如： It happened that I was out that day.
We don’t know
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. -- It’s certain that we shall be late. 1. That the earth is round is known to all.
3)连接副词when，where， how， why等。
How this happened is not clear to anyone. When he will be back depends on the weather. When we’ll start tomorrow will be told soon. Where the test will be given is not yet decided.