高中英语语法精讲(Unit18NewZealand)大纲人教版第一册.doc

语法精讲The Use of “It” (1) as Subject“It”的用法(1)作主语1.it用作人称代词，指前面提到过的人或物。The frog is not a warmblooded animal.It is a coldblooded one.青蛙不是温血动物，而是冷血动物。(指代the frog)Who is knocking at the door?谁在敲门？It is me.是我。(指代人)What is this?那是什么？It is a flag.It is hers.是一面旗，那是她的。(指代this或that)2.it也可用作非人称代词，表示天气、日期、时间、温度、距离、环境情况等。It was very noisy at the moment.现在外面很吵。(指环境情况)What time is it?几点了？It is eight oclock.8点了(指时间)It is five kilometers from the office to my home.从办公室到我家5千米。(指距离)3.it常用作形式主语或形式宾语，而把真正的主语或宾语(不定式、动词ing形式或名词性从句)置于句尾，以满足句子的需要。it作形式主语，常用于下列结构：1)It is+cruel(kind,brave,nice,rude,wise,stupid,clever;foolish,polite.)of sb. to do sth.2)It is important(necessary,possible,impossible,easy,difficult,hard.)for sb. to do sth.如：It is foolish of you to waste money.(=You are foolish to waste money.)你浪费钱是愚蠢的。It is necessary for us to study hard.(=To study hard is necessary for us.)对我们来讲努力学习是必要的。在这两个结构中，使用介词for还是介词of由前面的形容词而定；若形容词修饰人，使用介词of;若形容词修饰事，则使用介词for。3)It is no use(useless,no good)doing sth.It is no use talking with him.跟他谈话是没有用的。此结构中真正的主语通常为动名词。4)It is said(known,reported,thought,hoped,believed,announced.)that.It is said that he comes from America.据说他来自美国。此结构中真正的主语是名词性从句，且能变为简单句，上句可变为：He is said to come from America.即：从句的主语用作主语，谓语动词仍是主句的谓语动词，但应存在人称和数的变化，从句的谓语动词用不定式表示。如：It was known that he had gone abroad.=He was known to have gone abroad.众所周知他出国了。考题再现【考例1】（2006全国高考,26）If I can help _,I dont like working late into the night.A.soB.thatC.itD.them解析:此处考查it的用法。it可用于某些动词或前置词的后面，词义含糊，构成习语。如：Youll catch it!你可小心点儿!此处If I can help it意为“如果我有办法的话”。有时我们也可以说It cant be helped.或There is no help for it.表示“实在没法儿”。答案:C【考例2】(2006浙江高考，4)_ is our belief that improvements in health care will lead to a stronger,more prosperous economy.A.AsB.ThatC.ThisD.It解析:本句考查从句的用法。根据句子结构，that引导的从句为主语从句，作真正主语，因此前边应有形式主语，而形式主语只能用it,不能用this或that。答案:D【考例3】(2006山东高考，24)Id appreciate _ if you would like to teach me how to use the computer.A.thatB.itC.thisD.you解析:it作appreciate的形式宾语，真正的宾语是if you would like to teach me how to use the computer。it常在hate,like,appreciate等动词后作形式宾语，指代it之后的内容，对此用法应熟练掌握。答案:B【考例4】(2006全国高考,11)It is no _ arguing with Bill because he will never change his mind.A.useB.helpC.timeD.way解析:It is no use+doing.表示“做某事没有用”。it作形式主语，doing sth.作真正的主语。答案:A【考例5】(2006山东高考，33)Police are now searching for a woman who is reported to _ since the flood hit the area