1、zxxkw学科网学.科.网1.it作人称代词,代替前面提到的事物.2.it指代时间,季节,距离.3.it作形式宾语,常用在6123结构中.(think,find,make,believe,)4.it作形式主语.当动名词,不定式,从句作主语时,常用it作形式主语.5.It is that.的强调句型.内容提要1代替上文中提到过的人或事物。指代人时，一般用于小孩或身份不十分明朗的人。例如：Who is the baby?Its my teachers sonWho is that gentleman?Its my friend,TomHe(不可用It)wants to see you【典型例题】(
2、NMET2001)The Parkers bought a new house but _ will need a lot of work before they can move in.A.they B.it C.one D.which B2用于表达天气、环境、时间、距离、季节等。Its half an hours walk from here to our school Its nice and warm hereBut its two oclock now,and its time for us to go to school注意下列几种表示时间的句型zxxkw学科网.It is tim
3、e(about time,high time)that.Its high time that we left.It is the first(second.)time that.Its the first time that I have been praised.It is.since.Its three years since they got married.It is/was.when.It was 1949 when the PRC was founded.It is/was.before.It will be two years before we meet again.3.We
4、think it important to learn a foreign language.该句型中的it 作形式宾语。为了记忆方便我们可称该句型为“6123结构”。6 指主句中常用的动词：think,believe,make,find,consider,feel；1 指的是形式宾语 it；2 指的是宾补的两种形式：形容词或名词；3 指的是真正宾语的三种形式：不定式短语,动名词短语或 that 引导的宾语从句。4.It is necessary(for sb.)to do sth.此句型中的真正主语是不定式短语，主句中的形容词通常是表示重要性，紧迫性，频繁程度，难易，安全等情况的形容词，常见
5、的形容词有：important,necessary,natural easy,safe,common,normal,hard,difficult,dangerous,unusual,rare,impossible,pleasant在中的形容词作表语可以用从句改写，如：It is important for her to come to the party.=It is important that she(should)come to the partyzxxkwIt作形式主语时的几个常见句型:.It is kind(of sb.)to do sth.该句型中的不定式如果须要逻辑主语，则须要前
6、置介词 of,而句型中的形容词必须是能表示逻辑主语特征的形容词，常见的有：bad,brave,careless,clever,cruel,foolish,good（好心的）,honest,horrible,kind,lazy,modest,naughty,nice（有教养的）,polite,rude,silly,stupid,wise,wrong这个句型可以改写为：sb.is kind to do sth.It takes sb.to do sth.“做要花某人”It took me ages to repair my computer.It is no good(use)doing sth.
7、该句型中的真正主语是动名词短语，主句中的表语可以是 no good,no use,no value,no importance Its no use crying over the spilt milk.It doesnt matter whether(if).不论（是否）没关系 It doesnt matter whether he is for my plan or not.It happens(seems,appears)that.It happened that I had seen this problem in some book.It is said(reported,learn
8、ed.)that.“据说”（据报道，据悉）It is said that he has gone to New York to attend a medical meeting.It is a pity(a shame.)that.It is a pity that we have lost the match with a close score.It is important(necessary,right,strange,natural.)that.记住that 后的从句应用虚拟语气（should+动词原形），should 可以省去.It is suggested(ordered.)th
9、at.that 后的从句要用虚拟语气（should+动词原形），should 可以省常译为据建议；有命令）.It is up to sb.to do sth.该句型为“该由某人做”。该句型中up后的to是介词。It is up to him to clean our classroom today.今天应由他做教室清洁。It is up to parents to teach their children manners.该由父母教孩子礼貌。5.It is+被强调部分+that.将被强调的部分放在前面，其它部分置于 that 之后被强调部分可以是主语，宾语，表语或状语强调的主语如果是人，tha
10、t 可以由 who 换用如果把这种句型结构划掉后，应该是一个完整无缺的句子这也是与其 它从句区别判断的方法注意:It is not until+被强调部分+that.强凋“直到才”，需将 not 置于until 之前1.It was about 600 years ago _ the first clock with face and an hour hand was made(NMET97，单项填空)AthatBuntil CbeforeDwhen 2._computers play such an important part in our daily life?AWhy it is thatBWhy is it thatCWhy was it thatDWhy is it BA3.It was only when I reread his poems recently _I began to appreciate their beautyAuntil BthatCthenDso4.It was how the young man had learned five foreign languages_ attracted the audiences interest.A.so that B.that C.what D.in whichBB
