主语从句用法小结
请观察下列句子, 注意主语从句的特点。
1. That the earth travels round the sun is a well-known fact.
2. Whether the artist can do it or not is uncertain.
3. Who will act the lead in the play has not been decided yet.
4. Where the young man has gone is not known.
5. When and where the test will be given is not yet decided.
【归纳总结】主语从句必须有引导词；主语从句用陈述句语气。
1. 引导主语从句的词有：
连词: that, whether；
连接代词: who, whose, whom, whoever, what, which等；
连接副词where, when, whenever, wherever, how, why等。
主语从句引导词的选择：
1).连接词: that, whether
(1) That he will win is certain.
(2) It has been reported that sales of beef in China will increase.
(3) Whether we shall raise ducks or geese remains to be decided.
(4) Whether he ’ll join us in the discussion is of great importance.
2) 连接代词: who, whom, whose, what, which, whoever, whatever, whichever等。
(1) It is clear who is afraid of having a change in land ownership.
(2) Whose bag it is cannot be told.
(3) What India needs is a law to make land ownership fairer.
(4) It is not yet decided which cash crop will be produced next year.
(5) Whatever he said was right.
(6) Whoever go there must get ready by 6 o’clock.
3) 连接副词: when, where, why, how, how many, how much ,how long, how soon, how often等。
(1) When we’ll start tomorrow will be told soon.
(2) Where we can buy oxen is something we need to find out.
(3) How/ When he came here is not known.
(4) How we can protect the grain needs to be discussed.
(5) How many people died from starvation that year will never be known.
(6) How often he’ll go to see his grandmother depends on the time he can spare.
归纳总结：
主语从句引导词的选择主要是根据从句的结构和意义来选择。
1.如果从句的意义和结构完整，则用that。
2.如果从句的意义和结构不完整，则根据从句的意义和结构选择相应的引导词。比较that / what
1. What he wants is a book.
2. That he wants to go there is obvious.
3. What happened is not clear.
4. This is the best TV that is made in China. 定语从句
5. The first museum that he visited in China was the History Museum. 定语从句that 和what 的选用：that 和what 都可引导主语从句。但是，what除起连接作用外，还在主语从句中充当成分，可做从句的主语、宾语、或表语。而that 在主语从句中不充当任何成分，只起连接作用。
翻译和分析下列句子：
1. It is well reported that a storm is coming.
2. It is true that the earth moves around the sun.
3. It is a pity that I missed the train.
4. It doesn’t matter whether he will come or not.
5. It seems that it is going to rain.
6. It happened that they didn’t know my address.
归纳：为了使句子保持平衡，常用it来代替主语从句，而把主语从句放到后面，尤其是连词that引导的主语从句常用于此种句式中。
常用句型如下：
It+ be +名词+ that 从句
It+ be + 形容词+ that从句
It+ be + 动词的过去分词+ that从句
It+ be + 不及物动词+ that从句
1. It’s likely/possible/important/necessary/clear that…
很可能/重要的是…/必要的是……/很清楚…
2. It’s known/reported/ thought/said that…据说/据报道…
3. It seems/appears/happens that…显然、明显、碰巧.…
