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。 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: 由 that 引导的主语从句有时为了使句子结构平衡 , 避免
“头重脚轻”, 常 用 it 作形式主语, 而把从句放在后面。 例如: 1. That he will refuse this piece of advice is impossible. 2.That they should like each other is natural. 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 ______________(很遗憾)we lost the match. _____________(这是事实)he cheated in the exam. 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 ________________(很可能)she will come back tomorrow. *_________________(很明显)this measure is effective. 3) It +不及物动词+从句 It happened that... 碰巧…… It occurred to me that…我突然想起… _______________(刚好)I came into the office at that time. *____________________(我突然想起)I forget to sent the letter. 4) It + be +过去分词+从句 It is said that... 据说…… It is known to all that... 众所周知…… It is reported that... 据报道…… It is believed that..人们相信…… It is suggested that + (should）do... 建议…… It must be admitted that…必须承认…… It cannot be denied that… 不可否认…… It must be pointed out that…需指出的是…… __________________(据报道)20 people were killed in the accident. *_______________(建议)we should eat more vegetable and do more exercise.
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。它们在句子中担任主干成分，并用陈述句形式) What many scientists believe is that the earth is round … Who will take part in the meeting has not been decided. Whoever breaks the law will be punished. Whatever was said here must be kept secret.
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. How we will paint the house has not been decided.
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 2) whether 引导主语从句，if 不可 误：If Mary really heard him is really doubtful. 正: Whether Mary really heard him is really doubtful. Complete the sentences using what, whether, where, when， who, why, how or that. 1.(_____ is needed for success) is your hard work. 2.2.(______ they will arrive )has been told to the teacher. 3.(_____ we will go tomorrow )hasn’t been decided yet. 4.(______ can join in the sport meet) is decided by the teacher. 5.(________ it will rain or not) is not clear. Conclusion:主语从句作主语时，谓语动词一般用单数形式。 主语从句的规律：
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。 例 2. He will not come to the meeting this evening is true. 正：That he will not come to the meeting this evening is true. 规律二、连词 that 在从句中无实际意义， 但不能省略。
If the meeting will be put off has not been decided yet. 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 例 4. That whether he will help others is a fact. 正：That he will help others is a fact. 规律四、主语从句中的连词不能重叠使用。 例 5. When he will come are a puzzle. 正：When he will come is a puzzle. 规律五、含主语从句的主句谓语动词多用 单数第三人称形式。 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。 That the earth turns around the sun is known to all. It is known to all that the earth turns around the sun.
1.Where shall we spend the holiday isn’t decided. 2.You have made a mistake is a fact. 3. If the policeman will come is not certain. 4. That is certain that we can win. 5. It is ordered we should leave at once. 6. Where he comes from are a mystery. 7. What whether he likes the job is not clear. 8. Who he is and where he is from is important. 9.What he saw is the stars in the sky.
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 3. It worried her a bit ___ her hair was turning gray. whether B. that C. what D. when 4.What I say and think ___ none of your business. A. is B. are C. has D have
请用恰当的主语从句连词填空: What ,it ,that , whether, whoever
1. _____ you don’t like him is none of my business. 2. _____ he said at the meeting astonished everybody present 3. ________ the 2000 Olympic Games will be held in Beijing is not known yet. 4. ________ we’ll go camping tomorrow depends on the weather. 5. ________ leaves the room last ought to turn off the lights.
用 whether\if 填空
1.The question is ________ the film is interesting. 2.________ we shall attend the meeting hasn't been decided yet.
Correct or not?
If we will have a meeting hasn’t been decided yet. Whether we will………………………….decided yet. Pay attention:放在名词性从句句首，表示“是否”，只能用 whether, 不能用 if
That she wants to know is when the party will be held . What she wants to know is……. Pay attention:此主语从句缺少成分-宾语， 故用作成分的 what 来引导， 而不用 that
He will give up his job surprises all of us. That he will give up……… Pay attention:由 that 引导的主语从句放在句首，that 不能省略。
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 3.___ is known to us all that America is a developed country . A Which B As C What D It It’s known to us all ___ a form of energy .A. water is B. that water is C. is water D. that water to 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