(共18张PPT)
Section Ⅲ Grammar——主语从句
内 容 索 引
·感知·语法规律
·图解·语法脉络
·精讲·语法知识
观察下面的句子,并感知主语从句的用法。
1.However,what concerned him most was that farmers often had poor harvests and sometimes even had a serious shortage of food to eat.
2.How this could be done was a challenging question at the time.
3.Today,it is estimated that about 60 percent of domestic rice consumption in China is comprised of crops generated from Yuan’s hybrid strains.
4.What Yuan Longping really cared about was not money or celebrity.
一、主语从句的用法
主语从句是名词性从句的一种,在复合句中作主语,相当于名词。主语从句的位置可以在句首,也可以用it作形式主语,主语从句放在后面。
二、主语从句的引导词
1.连词that/whether,在主语从句中不充当任何成分,只起连接作用,不可省略,其中that没有词义,whether表示“是否”含义,但是不能换成if(如果)。
2.连接代词what/who/which,在主语从句中充当主语、宾语、表语,不可省略。
3.连接副词when/where/how/why,在主语从句中作状语,分别表示时间、地点、方式、原因,不可省略。
4.另外,wh-+ever如whoever/however/whatever/whichever等也可引导主语从句,在句中充当主语、宾语、表语等,不可省略。
That you are coming to London is the best news I have heard this long time.
你将来伦敦是好久以来我听到的最好消息。
Whether they would support us was a problem.
他们是否会支持我们还是一个问题。
What struck me was that they have all suffered a lot.
给我很深印象的是他们都受过很多苦。
Whichever (of you) comes in first will receive a prize.
无论(你们)谁取得第一名都会得奖。
How this happened is not clear to anyone.
这件事怎样发生的,谁也不清楚。
①____________ I’m hoping to accomplish is that my generation and younger start to reconsider and understand that jazz is not black and white any more.(全国卷Ⅰ)
②____________ he will attend the meeting or not doesn’t matter.
③___________________________________________ was a wonder.
他在那次严重的交通事故中幸存下来是个奇迹。
单句语法填空/补全句子
What
Whether
That he survived the serious traffic accident
④________________________ was a challenging question at the time.
如何做到这一点在当时是一个具有挑战性的问题。
⑤_____________________________ ought to turn off the lights.
无论谁最后离开房间都应该关灯。
How this could be done
Whoever leaves the room last
三、it作形式主语的主语从句
在主语从句中如果主语太长,宾语或表语又太短了,为了避免头重脚轻,保持句子平衡,通常会采用it作形式主语,真正的主语从句放在后面。
常见的使用it作形式主语的句型:
(1)It+be+形容词+that从句
常见形容词:necessary,likely,clear,right,important,possible,strange
(2)It+be+过去分词+that从句
常见过去分词:said,believed,reported,thought,known
(3)It+特殊动词(短语)+that从句
常见特殊动词(短语):seem,appear,happen,turn out
(4)It+be+名词(词组)+that从句
常见名词(词组):a pity,a shame,no wonder,good news,no surprise
It was a pity (that) you didn’t go to the talk. 很遗憾你没去听报告。
It is said that the expressway will be open to traffic next year.
据说这条高速公路明年通车。
It happened that I was out when he called.
他打电话的时候,我恰巧出去了。
①_______________________ I met my teacher on my way home.
我在回家路上碰巧遇上我的老师。
②_______________________ my fellow guests had only a few bites of each dish.
怪不得跟我在一起吃饭的客人,每道菜也就浅尝几口。
补全句子
It happened that
It was no wonder that
四、主语从句的语序和时态问题
1.主语从句和其他名词性从句一样必须使用陈述语序,尤其是当主语从句是疑问词引导的时候,主语从句的语序仍须使用陈述语序。
Who/Whom he will go to Beijing with remains unknown.
他将和谁一起去北京还不知道。
2.主语从句的时态需要根据具体语境来确定,尤其是当when引导主语从句的时候,有些同学会和when引导的时间状语从句混淆而误用现在时表将来。
When he will come back is still unclear.
他什么时候回来还不清楚。
①____________ is impressive is that my colleagues messaged us,worrying why Kun and I didn’t come back with the clock pointing to 1 am,2 am or even 3 am.
②____________ worries many people is that these chemicals may even cause cancer.
③____________ breaks the law should be punished.
单句语法填空
What
What
Whoever
五、主语从句作主语时谓语动词的单复数
主语从句作主语相当于名词,和非谓语动词的动词-ing形式或者不定式作主语一样看作单数,句子谓语应该使用单数形式。what引导的主语从句,谓语动词通常用单数,但所指的具体内容是复数意义时,谓语动词可用复数形式。
That you don’t like him is none of my business. 你不喜欢他不关我的事。
What the doctors really doubt is whether my mother will recover from the serious disease soon.
医生们真正怀疑的是我妈妈是否不久就能从这场重病中恢复过来。
What are often regarded as poisonous fungi are sometimes safely edible.
通常被认为有毒的真菌有时可以安全食用。
①Whether it will do us harm or good ____________ (remain) to be seen.
②What are used as chief building materials today ____________ (be) steel and concrete.
③What we can’t get ____________ (seem) better than what we have.
单句语法填空
remains
are
seems
Thanks!
本节内容结束