14It的用法语法点及练习

《高中英语语法大全》第14章“It”用法及其句型和固定搭配It用法及其句型和固定搭配，是高中英语语法的重点、难点，又是近几年高考的热点，因此应给予充分的重视，现将it用法归纳如下：一、It用作实词表达以下概念:指代前文提到的事物，前文中的this,that；替代前文中的内容；指代一位性别不明的小孩或未知的人；指代未指明但谈话双方都知道的那件事；指代时间、天气、气候、距离等自然现象……二、It用作形式主语替代作主语的从句、动词不定式、动名词，而把真正作主语的从句、动词不定式、动名词置于句尾。It作形式主语的常见句型：1.代作主语的动词不定式，其句型为(1)Itbeadj.(forsb.)todosth.此处adj.通常为描述事件的形容词：easy,difficult,hard,necessary,unnecessary,possible,impossible,likely,unlikely,right,wrong,important,unimportant,legal,illegal,well-mannered,ill-mannered,polite,impolite,clear,obvious,certain,suitable,proper,fit,useful,useless,dangerous…例Itisillegal(forateenager)todriveacarwithoutalicense.(2)Itbeadj.ofsb.todosth.此处adj.通常为描述人的形容词：kind,unkind,nice,rude,cruel,considerate,thoughtful,thoughtless,careful,careless,silly,foolish,stupid,clever,wise,crazy.例It'skindofyoutohelpmewiththeproblem.(3)It替代作主语的动名词的常见句型It'snogood/usedoing…It's(well)worthdoing…It's(well)worthone'swhiledoing/todo…It's(well)worthwhiledoing/todo例It'snousecryingoverspiltmilk.2.It替代作主语的从句常见句型(1)Itis+noun+从句例Itisnosecretthatthepresidentwantstohaveasecondtermatoffice.(2)Itisadj.+clauseIt'ssurprisingthat…(should)………竟然……It'sapity/shamethat…(should)………竟然……例It'simportantthatyoushouldapologizetoherforyourrudeness.(=It'sofmuchimportancethatyoushouldapologizetoherforyourrudeness.)(3)Itverbsb.+clause=Itisv-ing+clauseIt+surprise/delight/interest/disappoint/worry/disturb/annoy/amaze/bother/concern/frighten/please/angersb.that…例Itworriedmethatshedrovesofast.(=Itwasworryingthatshedrovesofast.)(4)Itverb(tosb.)that…=sb/sthverbtodo(verb=appear,seem,comeabout,emerge,follow,chance,happen,occur,transpire,turnout,workout)例It(so)happened/chancedthattheywereout.(=Theyhappened/chancedtobeout.)(5)Itisv-edthat…=sb/sthistodo(verb=say,report,think,believe,hope,expect,agree,accept,decide,determine,intend,plan,understand,know）例Itissaidthatthecouplehavegottendivorced.(=Thecouplearesaidtohavegottendivorced.)(6)Itisv-edthat…(should)…(verb=demand,request,require,order,suggest,advise,recommend例Itissuggestedthattheyshouldbeginwiththethirdquestion.三、It作主语的句型1.Ittakessb.…todo…(=sbtakes…todo…)某人用多长时间做某事例Ittookthemenaweektomendourroof.(=Thementookaweektomendourroof.)2.It's(just)(un)likesb.todo…（不）像某人做某事的风格例Itwas(just)likehimtothinkofhelpingus.3.It's(about/high)timethat…should/v-ed…是该做某事的时候了例It's(about/high)timethatweshouldtakeaction.4.It'sthex-thtime(that)…havev-ed…第几次做某事了例It'sthethirdtimethathehasfailedthedrivingtest.5.Itis/hasbeen…since…continuousv-ed(延续性动词)某动作已有多长时间不发生了例It's10yearsthathelivedhere6.Itwas(not)…before…过(不)了多长时间某动作发生了例Itwasnotlongbeforetheyarrived.四、It作形式宾语用来替代作宾语的从句、动词不定式、动名词，而把真正作宾语的从句、动词不定式、动名词置于句尾。It作形式宾语的常见句型：1.verb+it+adj./noun(for/of)todo/clause(verb=think,believe,suppose,consider,feel,make,keep…)例Ithinkithardforyoutodothetaskonyourown./Ithinkithardthatyou'lldothetaskonyourown.2.verb+it+adj./noun(one's)doing(adj.=useless/worth/worthwhile)(noun=nouse/nogood/worthone'swhile/awasteoftime/money/energy/words)(verb=think,believe,suppose,consider,feel,make,keep…)例I'llmakeitworthyourwhiletellingmeabouthissecret.3.verb+it+important/unimportant/necessary/unnecessary/natural/essentialthat…(should)…verb+it+ofmuch/great/no/littleimportancethat…(should)…(verb=think,believe,suppose,consider,feel,make,keep…)例Ithinkitimportantthatyou(should)attendtheconference.4.verb+it+as+noun/adj.+clause(verb=accept,regard,take,see,view)例Thelecturertakesitasencouragingwhensomanystudentsattendhislecture.5.v.+it+prep.+that…oweittosb.that…把…归功于…leaveittosbthat…把…留给某人去做takeitforgrantedthat…想当然keepitinmindthat…例Don'tbothertoarrangeanything.Justleaveittometosortout.6.It用在不能直接跟宾语从句的动词后面，尤其是表示好恶的动词后，enjoy,like,love,dislike,resent,hate,don'tmind,befondof,feellike,seeto宾语从句紧跟it之后例IhateityoucanswimsowellandIcan't.7.It用在不能直接跟宾语从句的介词后面，宾语从句紧跟it之后（exceptthat例外）例I'mforitthatyouwillfollowtheiradvice.五、强调句型Itis/was+被强调部分+that(who)…强调句型用来强调谓语动词以外的任何句子成分。当被强调部分是人时也可以用who。在使用强调句型时需注意以下几点：1.请注意强调句型的特殊疑问句例Whenwasitthathechangedhismindtotakepartintheactivity？2.在强调原因状语从句时，只能强调由because所引导的从句例Itwasbecausehewasillthathedidn'tcometoschoolyesterday.3.在强调not…until结构时必须把not与until一起放到被强调的位置上例ItwasnotuntilshetookoffherdarkglassesthatIrealizedshewasmybrother.4.注意强调句型与定语从句的区别例Itwasat7o'clockthathecamehereyesterday.(强调句型)Itwas7o'clockwhenhecamehereyesterday.(定语从句)六、It常用的固定搭配1.makeit(1).在口语当中相当于succeed,表示：成功、做到、说定、赶上、及时到达例It'shardtomakeittothetopinshowbusiness.(2).在口语中相当于fixthedatefor,表示“约定好时间”例—Shallwemeetnextweek?—OK.WejustmakeitnextSaturday.2.asitis(1).相当于infact,inreality表示“事实上，实际情况是……”例Wehadplanedtofinishthetasktoday,butasitisweprobablywon'tfinishituntilnextweek.(2).相当于方式状语从句，表示“照原样”例Leavethetableasitis.3.asitwere相当于asonemightsay,thatistosay,表示“也就是说，可以说，换句话说”例Heis,asitwere,amodernSherlockHolmes.4.ifitweren'tfor…/ifithadn'tbeenfor…用来引导虚拟语气，相当于without,orbutfor,表示“如果不是……，要不是……”例Ifitweren'tforTom,Iwouldn'tbealivetoday.5.that'sit(1).相当于That'sall.That'ssomuch.表示“至此为止，没有别的了”例Youcanhaveonemoresweet,andthat'sit.(2).相当于That'sright.表示“对啦”例—Iguessthekeytotheproblemisthechoice“A”—That'sit.6.catchit在口语中，相当于bepunished/scoldedfor