2.引导词it
1)作形式主语。当动词不定式、动名词或从句作主语时,通常把它们放在谓语之后,而用it作句子的形式主语。例如:
It is not a good habit to stay up late.
It is no use asking him.
It is said that he is still living.
It's high time that Robert went to school.
It is a pity that you didn't read the book.
2)作形式宾语。当复合宾语中的宾语是不定式、动名词、宾语从句时,往往把宾语放在它的补足语后面,而用it作形式宾语,放在宾语补足语之前。例如:
I think it no use arguing with him.
I found it very interesting to study English.
He made it clear that he was not interested in this subject.
3)用于强调结构。要强调句子的某一部分(通常是主语、状语、宾语),可以把it当作先行词。这种句子的结构是"It is(was)+被强调部分+that(who)+句子的其余部分"。如果被强调的部分是人可用who,whom代替that。例如:
The parents will never forget that it was he who had saved their child's life.(强调主语)
It was the kind of work that I liked.(强调宾语)
It was at twelve o'clock that BBC gently informed its listeners that it was an April Fool trick.(强调状语)
It is all because you're a fool that I'm often ill.(强调状语从句)
使用It强调句式要注意以下几个问题:
①对特殊疑问句中的特殊疑问代(副)词强调时,特殊疑问代(副)词要放在句首,原问句中特殊疑问词后的一般疑问语序要变成陈述语序,It is/was...that/who...句式也要相应地变成一般疑问语序。例如:
When did you meet Mr.Smith.(对when强调)
→When was it that you met Mr. Smith.
要特别注意的是,若对疑问代词who(m)强调,只能用It is/was...that...。例如:
Who told you the news.(对who强调)
→Who was it that(that不能用who代替)told you the news.
②句中的人称代词被强调时,应保持该人称代词格的不变和原句中谓语动词在人称和数上的不变。例如:
She loves him very much.(对him强调)
→It is him that/who she loves very much.
I am against this plan.(对I强调)
→It is I that/who am against this plan.
③对not...until...句型中的until...状语强调时,不仅要把until...状语置于It is/was之后,还要把not置于until之前,原来的句子要变成肯定句。例如:
Regular radio broadcasts didn't begin until 1920.(对until 1920强调)
→It was not until 1920 that regular radio broadcasts began.
④倒装句中的某一部分被强调后,原倒装句不再用倒装语序。例如:
Never has he seen a wolf be-fore.(对a wolf强调)
→It is a wolf that he has never seen before.
⑤It强调句式的判断方法。
It强调句式中被强调的成份是句中的某个成份。对句中某个成份进行强调,就是把该成份提到强调句式的It is/was之后,that/who之前。可以看出,强调位置上的成份正好是that/who后面的句子中所缺少的成份。因此,把一个句子中的It is/was...that/who...这一框架去掉以后,剩余的仍是一个完整的句子(若是强调宾语,需适当调整一下语序),我们就可以判断该句为强调句式。例如:
It was a factory that we visited last Sunday.若去掉It was...that...这一框架,剩余部分稍作语序上的调整可成为We visited a factory last Sunday.这是一个完整的句子,所以原句是强调句式。It is a fact that we visited a factory last week.若去掉It is...that...框架,剩余部分不是完整的句子,所以原句不是强调句式。(是一个含有主语从句的主从复合句)
⑥It强调句式的判断误区a.把it指时间、指天气、指环境、指距离等后接be...的情形误认为是强调句式。例如:
It was three o'clock__________we reached the village.
(A.that B.which C.when D.while)
该题正确选项为C,句意为:我们到达那个山村时,时间是三点钟。it指时间。由强调句式的判断方法可知,若将原题变为It was at three o'clock__________we reached the village.,则选A项构成强调句式。It was so long a way that we were all tired.该句意思是:路是那样的远,所以我们都觉得疲劳。其中it指距离,that引导结果状语从句。全句是一个含有结果状语从句的主从复合句,不是强调句式。b.把具有实际意义的指示代词it后接be...that(that引导定语从句)的情形误认为是强调句式。例如:
-What's on your desk.-Oh,it's the very dictionary that you've been looking for.此对话的意思是:"你书桌上放着什么.""正是你一直在找的那本词典。"其中it指代问句中的what,that引导定语从句修饰dictionary,全句是一个含有定语从句的主从复合句,不是强调句式。c.把充当形式主语的it后接be...that(that引起主语从句)的情形误认为是强调句式。如:
It is a pity that Jack should have missed the wonderful film.该句句意是:真可惜,杰克居然没看上那部好片子。
it是形式主语,that从句是真正的主语,全句相当于:That Jack should have missed the wonderful film is a pity.
vwey good
