主语从句-Aly

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. 或把if 改为whether
误：If Mary really heard him is really doubtful. 正：It was doubtful if Mary really heard him. 正: Whether Mary really heard him is really doubtful.
2) It is + adj. +从句 It’s certain that… 肯定… It is possible that... 很可能…… It is unlikely that... 不可能…… It is obvious that… 很明显… It is necessary \important \natural\... that… +(should) +do… It is possible that *_________________(很可能)she will come back tomorrow. It is obvious that *_________________(很明显)this measure is effective.
正： Whether the meeting will be put off has not been decided yet.
规律三、whether 可以引导主语从句， 放在句首，但if不能
主语从句的规律：
例4. That whether he will help others
is a fact.
主语从句的规律：
1. What he needs is that book. 2. What he needs are some books.
规律六、what 引导的主语从句，可根据 表语决定主句动词的单复数形式。
规律七、主语从句为了避免头重脚轻现 象，用 it 做形式主语，而 把从 句放在后面。
2.连接代词who ，what ，which, whatever, whichever, whoever (Who, whom, which, what可
以和ever构成合成词，和what一样引导从句，ever起到 强调作用。此类主语从句不能用形式主语it引导，它们在 句子中担任成分，不能省略，语序为陈述语序)
1. That he will refuse this piece of advice is impossible. It is impossible that he will refuse this piece _______________________________________ of advice. _______________________________________
4) It + be +过去分词+从句
It It It It It It It It
is said that... 据说…… is known to all that... 众所周知…… is reported that... 据报道…… is believed that...据信……;人们相信…… is suggested that + (should）do... 建议…… must be admitted that…必须承认…… cannot be denied that… 不可否认…… must be pointed out that…需指出的是……
That the earth turns around the sun is known to all.
It is known to all that the earth turns around the sun.
Exercises :
Part One: 主语从句单选题
1. D has helped to save the drowning girl is worth praising. A.Who B.The one C.Anyone D.Whoever 2.It was A he said disappointed me.
What many scieearth is round …
Who will take part in the meeting has not been decided.
Whoever breaks the law will be punished. Which student will win is uncertain. Whatever was said here must be kept secret. 这里说的话都应当保密。
Whoever makes mistakes must correct them. 凡犯了错误的人都必须改正。
3)连接副词when，where， how， why等。
Why they suddenly disappeared still remains a mystery.
When they will leave is not decided. Where she is from is unknown. How we will paint the house has not been decided.
3) It +不及物动词+从句 It happened that... 碰巧…… It occurred to me that…我突然想起…
It happened that *________________(刚好)I came into the office at that time.
*____________________(我突然想起)I forget to It occurred to me that sent the letter.
A.what ;that B.that; that C.what;what D.that;what 3. B we’ll go camping tomorrow depends on the weather.
A.If B.Whether C.That D.Where
4. A he said at the meeting surprised everybody present. A.What B. That C.The fact D.The matter
主语从句的规律： 找出下列句子中的错误，并总结规律 例1.When will he come is not known. 正：When he will come is not known.
规律一、主语从句一律用陈述语序， 即主语在前，谓语在后。
主语从句的规律：
例2. He will not come to the meeting this evening is true.
*it为形式主语
2.That they should like each other is natural. It is natural that they should like each other. _____________________________________
这样就构成了下面一些常用句型: 1) It is + n. +从句 It is a pity/shame that... 遗憾的是…… It is a surprise that…令人惊奇的是… It is a fact that… …是事实 It is common knowledge that… …是常识 It is a pity that *_______________(很遗憾)we lost the match. It is a fact that *______________(这是事实)he cheated in the exam.
4.(______ can join in the sport meet) is decided by the teach Who 5.(________ it will rain or not) is not clear. Whether
Conclusion: 主语从句作主语时，谓语动词一般用单数形式。
That he will win is certain.他肯定会赢. Whether he’ll come here isn’t clear. 他是否会来这里还不清楚。
注意:
轻”, 常用
由that 引导的主语从句有时为了使句子结构平衡, 避免 “头重脚
it 作形式主语, 而把从句放在后面。 例如:
It is reported that *___________________(据报道)20 people were killed in the accident. It is suggested that
*______________________(建议)we should eat more vegetable and do more exercise.
Grammar
Grammar
主语从句：
做主语用的名词性从句，因其在复合句中做主语， 又称主语从句，引导主语从句的有连词that ， whether， 连接代词who ，what ，which， 连 接副词when，where， how， why等。
1）从属连词：that， whether等. that 引导主语从句只起引导作用，本身无实 际意义，在主语从句中不充当任何成分，但 不能省略。
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；但是如果用it 做形式主语，而把主语从句放在句末时， 从属连词that可以省略。
误：They should like each other is natural. 正：That they should like each other is natural. 正：It is natural (that) they should like each other.