初中英语重点语法：主语从句
一、主语从句的概念与类型
主语从句在复合句中作主句的主语,引导主语从句的词有从属连词that, whether以及连接代词who, what, which, whoever, whatever, whichever和连接副词when, where, why, how等.
例如:
That she was chosen made us very happy.
她当选了使我们很高兴.
What caused the accident is a complete mystery.
是什么导致了这次事故还完全是一个谜.
Whether she will come or not is still a question.
她是否来还是一个问题.
Which team will win the match is still unknown.
哪个队会赢得这场比赛还不知道.
Whoever comes to the party will receive a present.
参加聚会的每一个人都将收到一份礼物.
When they will start has not been decided yet.
他们何时出发还没决定.
注意:上述例句中的主语从句都是放在句首,但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:
It is a pity that she has made such a mistake.
她犯了这样一个错误,真是遗憾.
It depends on the climate whether they are going shopping today.
他们是否今天去购物还得看天气情况.
这样就构成了下面一些常用句型:1)It is + adj./ n.
+从句It is a pity/shame that...
遗憾的是……It is possible that...
很可能……It is unlikely that...
不可能……2)It +不及物动词+从句It seems/appears that...
似乎……It happened that.
碰巧……3)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.
据信……;人们相信……It is suggested that.
有人建议……It must be pointed out that.
必须指出……It has been proved that.
已证明…….
例如:It is believed that at least a score of buildings were damaged or destroyed.
据信,至少有二十座楼房遭到破坏或彻底毁掉.
It is suggested that the meeting should be put off.
有人建议会议延期召开.
It s reported that three people were killed in the accident and five were hurt badly.
据报道,事故中三人丧生,五人重伤.
It is known to all that Taiwan is an inseparable part of China.
众所周知,台湾是中国不可分割的一部分.
[巩固练习]
1. Does _______ matter if he can t finish the job on time?
A.this
B.that
C.he
D.it
2.It worried her a bit _______ her hair was turning grey.
A. which
B. that
C. if
D. for
3._______ is a fact that English is being accepted as an international language.
A. There
B. This
C.That
D. It
二、学习主语从句应该注意的几个问题
1)引导词that与what
what既有引导主语从句的作用,同时又在从句中作句子成分(主语、宾语、表语等).
这时what相当于all that/everything that,常译成'所……的(东西、事情、话等.)';而that只起连接作用,本身无实际意义,在从句中也不担当任何句子成分.
但that引导的主语从句放在句首时,不能省略that.
例如:
What is done can t be undone.
(谚语)已成定局,无可挽回.
What we can t get seems better than what we have.
我们得不到的东西似乎比已得到的要好.
That we should work out a plan to deal with the present serious situation is important.
我们应该制定一项计划来应付目前严峻的形势,这一点非常重要.
That a new teacher will come to teach us geography is true.
一位新老师将来教我们地理,这是真的.
[巩固练习]
4._______ what they told me really true?
A. Has
B. Is
C. Does
D. Have
5.It matters little _______ a man dies, but _______ matters much is _______ he lives.
A.how; what; how
B. how; it; how
C.why; it; why
D.that; what; that
6. _______ she couldn t understand was _______ fewer and fewer students showed interest in her lessons.
A. What; why
B. That; what
C. What; because
D.Why; that
7. It is pretty well understood _______ controls the flow of carbon dioxide in and out the atmosphere today.
A.that
B.when
C. what
D. how
8._______ fashion differs from country to country may reflect the cultural differences from one aspect.
A.What
B. That
C. This
D.Which
9.-What made her parents so angry?- _______ she had failed in the examination.
A. As
B. Because
C. Since
D. That
2)引导词if和whether if和whether引导动词后的宾语从句时一般可通用,但介词后的宾语从句、主语从句(放在句首时)、表语从句常由whether引导.
例如:
Whether she will go home or not is unknown.
她是否回家还不得而知.
Whether we shall raise ducks or geese remains to be decided.
我们是养鸭还是养鹅仍没决定.
=It remains to be decided whether/if we shall raise ducks or geese.
[巩固练习]
10._______ we ll go camping tomorrow depends on the weather.
A.If
B. Whether
C. That
D. Where
3)其它引导词连接代词who, which, whom, whose有各自的意义,起连接作用,并在从句中充当语、宾语、表语、定语等;连接副词when,where, why, how等有各自的意义,起连接作用,并在从句中充当状语.