主语从句语法详解
在英语中，主语从句是非常重要的一个语法知识，主语从句涉及的知识也非常多，需要我们耐心去理解，要不然容易混淆。下面是小编给大家带来的英语语法主语从句_主语从句语法详解，以供大家参考，我们一起来看看吧!
▼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 completemystery.
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 stillunknown.
哪个队会赢得这场比赛还不知道.
Whoever comes to the party will receive apresent.
参加聚会的每一个人都将收到一份礼物.
When they will start has not been decidedyet.
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 amistake.
她犯了这样一个错误,真是遗憾.
It depends on the climate whether they aregoing 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 ofbuildings 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 beput off.
有人建议会议延期召开.
It&39;s reported that three people were killedin 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 aninseparable part of China.
众所周知,台湾是中国不可分割的一部分.
主语从句语法详解精选篇1
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&39;t be undone.
(谚语)已成定局,无可挽回.
What we can&39;t get seems better than what wehave.
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 serioussituation 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 usgeography is true.
一位新老师将来教我们地理,这是真的.
主语从句语法详解精选篇2
<例句>
It&39;s certain that prices will go up.
物价肯定要上涨的。
<语法分析>
主语从句可以由that引导，此外还可由连接代词或连接副词引导，关系代词what或whatever也可引导主语从句。由that引导的主语从句是用的最多的一种主语从句，有时为了强调，可以把从句放在句首，而绝大部分主语从句则借助先行主语放到句子后部去。
<触类旁通>
(1)That she hasn&39;t phoned is odd.
她没有来电话很奇怪。
语法分析：that引导的主语从句。
(2)That he was chosen made a tremendous stir in his village.
他被选中在他村子里引起很大轰动。
语法分析：有时为了强调或谓语较长时，可以把从句放在句首。
(3)It is natural that they should have different views.
他们有不同观点是很自然的。
语法分析：it+be+形容词或名词+that从句。
(4)It happened that he wasn&39;t in that day.
恰巧他那天不在。
语法分析：it+动词+that从句。
(5)It&39;s doubtful whether we&39;ll be able to come.
我们是否能来还是个疑问。
语法分析：连接代词或连接副词可引导主语从句。
(6)What will be,will be.
该发生的事，总会发生。
语法分析：关系代词型what也可引导主语从句。
<巩固练习>
(1)______ he is still alive is a consolation.
(2)It&39;s strange ______ she knows nothing about it.
(3)It may be ______ you&39;ll prove yourself the most suitable.
(4)______ is to be sent there hasn&39;t been decided.
(5)It was clear enough ______ she meant.
(6)______ is over is over.
(7)______ he says goes.
(8)______ she saw made her tremble.
<参考答案>
(1)That (2)that (3)that (4)What (5)what (6)What (7)Whatever (8)What
主语从句语法详解精选篇3
在It is necessary / natural/ important / strange...+ that-clause
这类句型里,that所引导的主语从句中谓语动词用"should+原形",表虚似语气.
例如:
It is necessary that the problem should besettled at once.
这个问题必须马上解决.
It&39;s strange that he should have gone awaywithout telling us.
他竟然没向我们说一声就走了,真是奇怪.
巩固练习
15. It isnecessary that a college student _______ at least a foreign language.
A. masters B.should master C. mastered D. will master
四、以it作形式主语的主语从句与强调句型的区别
"It be + adj./n. + that-clause"与强调句型均有It be...that...之类的语言标志,但不同的是:①前者中的that从句是主语从句.若删掉其中的It be和that,则剩余部分不论结构还是语意都不能成为一个句子;但若将后者中的It be和that去掉,则剩余部分的结构和语意仍能构成一个完整的句子.②强调句型译为汉语时可加上"正是……"或"就是……"之类的字眼,而主语从句则不可以.
请比较下面两个句子:
It is surprising that Mary should have wonfirst place.
令人惊奇的是玛莉竟然获得了第一名. It is Mary that has won first place.
正是玛莉得了第一名.
第一句话中的It是形式主语,that引导的是主语从句.句中的It is和that无法删除,一旦删除句子就不成立.
第二句是强调句型,其中的It is和that可以去掉,因为没有It is和that句子仍然很通顺.