It的用法归纳1.It指天气、光线、时间、距离、状况、环境情况等2.It可代替前面已经叙述过的名词（指事物，动物或很小的小孩），以及something,anything,everything,nothing，和不是指人的this,that等---其作用是避免同一个名词的重复。3.It代替前面已经说过的片语或从句，以避免重复。4.It用做形式主语1)用在一些固定的结构里。如；Itseems(appears,looks)that好象Ithappensthat碰巧Itoccurstosbthat某人想到Itisapity(ashame,afact,anhonor,awonder)that…Itisstrange(natural,possible,likely,quiteclear,unusual,etc.)thatsb.shoulddo…Itwassaid(reported,announced,arranged,decided,stressed,believed,etc.)that…Itdoesn’tmatter(doesn’tseemtomattermuch,doesn’taffectus,etc.)+连接代词或副词引起的从句2)不定式做真正的主语，用It作形式主语。3)动名词做真正的主语，用It作形式主语。常有以下几种结构：Itisuseless/nouse/nogood/notanyuse/notanygood/notmuchuse/notmuchgood+V-ingIsitanyuse/anygood+V-ing?Itisworth+V-ing5.It作形式上的宾语当句子的宾语是动词不定式或that从句时我们有时用It作形式宾语。6.Itis(was)+所要强调的部分（除谓语外）+that(orwho)+其余部分注：当强调部分是某人时，之后的关系代名词that和who都可以。7.It代表做某件事的人或辩明某人是谁。E.g.Whoisit?ItisMary.8.It的惯用语。E.g.Itisverykindofyou.(Youareverykind)Itisalloverwithus.(Thereisnohopeleftforus.)Howisitwithhim?(Howishe?)Thatisit.(That’swhatImean./That’swhatIwantedtoknow.)That’sthebest(worst)ofit!英语常用句型：Itissaid/reported/announced/estimatedthat…据说/报道/猜测/通告/估计Itisgenerallybelieved/thought/acceptedthat…人们普遍认为Itneveroccurredtosb.that…某人从未想到Itisknowntoallthat…众所周知Itreallymatters…真正重要的是Whatreallymattersis…ItisbettertodoAthantodoB比起B来，做A更好prefertodoAratherthandoB..宁愿做A而不愿做BwouldratherdoAthandoB…宁愿做A而不愿做Bso/such….that…如此…以至于…comparedwith….与…相比较Notuntil….didsb.doitisnotuntil…that….Hardlyhadsbdone…whensbdid…Nosoonerhadsbdone…whensbdid…Itisobviousthat显然Itisapitythat…可惜的是Iitseems/appearsthat…似乎Ithappenedthat…碰巧…think/feel/considerittodoItisnouse/gooddoing…做某事没有用处/好处Itisuptosb.todo某人有责任做某事Itistruethat…。。。是真的