大学英语语法讲解..

大学英语语法讲解情态动词的完成时(表示对过去的说法)must+have+过去分词（用于肯定句）一定已经…….Thelightisstillon.Theymusthaveforgottentoturnitoffwhentheylefttheroom.注:mustn’thavedone×can’t(couldn’t)+have+过去分词（用于否定或疑问句）不可能……..HecannothavebeentothattownforIsawhimjustnow.should/oughtto+have+过去分词本应该做(却没有做)…….Ashisbestfriend,youshould/oughttohavehelpedhim.(butinfact,youdidn’t.)shouldn’t/oughtnotto+have+过去分词本不应该做(却做了)…….Youshouldn’thaveparkedyourcarhere,forit’sapublicplace.needn’t+have+过去分词本不必做……Youneedn’thavewaitedforme.ItoldyouyesterdayIwouldoverwork.withwith+doneWiththehomeworkfinished,theboywentout.with+doingWiththeoldmanleadingtheway,wefinallyfindthehouse.with+prepWiththelighton,allthestudentswentoutoftheclassroom.虚拟语气的用法概念：表示说话人的愿望、假设、猜测、或建议，而不表示客观存在的事实。虚拟语气通过谓语动词的特殊形式来表示虚拟语气用于条件状语从句(1)与过去事实相反If…had+done,…would(should,could,might)+have+doneIfyouhadtakenmyadvice,youwouldn’thavefailedintheexam.与现在事实相反If+did(be→were)，…would(should,could,might)+doIfhehadtime,hewouldattendthemeeting.IfIwereyou,IshouldstudyEnglish.与将来事实相反If+did(be—were)/wereto/should+do,…would(should,could,might)+doIfyoucametomorrow,wewouldhavethemeeting.Ifitweretoraintomorrow,themeetingwouldbeputoff.虚拟语气用于宾语从句在表示建议、要求、命令类的动词后面的宾语从句中用(should)+do。如:advise,suggest,propose,request,require,insist,demand,order,command,desireWesuggestedthatwe(should)haveameeting.Weinsistedthatthemeeting(should)becancelled.注意：suggest作“暗示，表明”解时，insist作“坚决认为”解时不用虚拟语气，而用一般的时态。Mikeinsistedthathehadneverstolenanything.Hersun-tannedfacesuggestedthatshewasinexcellenthealth.虚拟语气用于主语从句Itisnecessary(important,natural,strange,essential,etc.)thatsb(should)+动词原形Thisisaverydifficultoperation.Itisessentialthatyoubepreparedforemergency.Itisbesuggested(desired,ordered,proposed,advised,etc.)thatsb(should)+do虚拟语气用于表语从句、同位语从句作advice,idea,order,demand,plan,proposal,suggestion,request，wish等名词的表语从句、同位语从句。其谓语动词用(should)+动词原形Weallagreedtohissuggestionthatwe(should)gotoBeijingforsightseeing.itis(high)timesb+didItis(high)timeweleft.虚拟语气用于ifonly引导的感叹句中(要是…就好了)IfonlyIhadtakenhisadvice.accountfor:解释某事物的原因Pleaseaccountforyourrudebehavior.bringup:抚养Shewasbroughtupbyheraunt.getthrough:(设法)完成;(使)通过Thereisalotofworktogetthrough.Shegotallherpupilsthroughthetest.trytodo:设法做某事Wetrytofinishtheworkontime.endeavor(fml.)todo:设法做某事Weendeavortofinishtheworkontime.succeed(in)doing成功做某事Wesucceedinfinishingtheworkontime.asaresult:结果Asaresult,twopeoplewerekilledintheaccident.bytheway:顺便Bytheway,pleasegiveittoMary.onthecontrary:与此相反Itdoesn’tseemuglytome;onthecontrary,Ithinkit’sratherbeautiful.pickout:挑出Hepickedouttheripepeach.makeout:辨认Canyoumakeoutwhatthatsignsays?giveoff:发出(蒸汽,光等)Thefoodgaveoffabadsmell.separate:分开separate…fromcompare:比较compare…to/with…contrast:contrast(to/with)…对比，相比comeupwith:提出Hecameupanewideaforincreasingsales.catchupwith:赶上Afteraterm,shecaughtupwiththeotherstudentsinherclass.keepupwith:跟上Weshouldkeepupwiththepaceofthemodernsociety.定语从句在复合句中修饰名词或代词的从句叫做定语从句。被修饰的名词或代词叫先行词。引导定语从句的关系代词有who,whom,whose,which,that等和关系副词when,where,why等。他们在定语从句中担任句子成分。who（代替人）:Iknowthemanwho/thatisstandingunderthetreeoverthere.whom:Thedoctor(whom)youarelookingforisintheroom.Whostandsneartheriverisourschool.whose（可代替人和物）DoyouknowthemanwhosenameisWangYu?Iliveinaroomwhosewindowsfacesouth.which（代替物）Thebuildingwhichstandsneartheriverisourschool.that(可代替人和物)Theletter(that)Ireceivedwasfrommyfather.注意:在下面几种情况下必须用“that”1.先行词是不定代词：all,few,little,much,something,nothing,anythingAllthat(what)wehavetodoistopractiseeveryday.2.先行词被序数词或形容词最高级所修饰。Thefirstlesson(that)Ilearnedwillneverbeforgotten.3.先行词被all,anyevery,few,little,no,some等修饰。Ihavereadallthebooks(that)yougaveme.whenIwillneverforgetthedaywhenImetMr.Liu.whereThisistheplacewherewelivedfor5years.whyIknowthereasonwhyhecamelate.限制性定语从句是句中不可缺少的组成部分，主句和从句之间不用逗号分开。非限制性定语从句一般用逗号把主句和从句分开。通常关系代词不能省略，不用that。Ihavetwosisters,whoarebothstudents.关系代词which，as可指代前面整句话的内容。Asweallknow,hestudiesveryhard.[P184第49题]倒装句英语的正常语序是主语在前，谓语在后。但有时为了强调或为了语法结构的需要，可以将谓语的全部或部分提到主语之前。这种语法现象叫做倒装。全倒装：把全部谓语放在主语之前。以out,in,up,down,away,here,there,等副词开头的句子里。Herecomesthebus.部分倒装：把助动词或情态动词放在主语之前否定副词提前的句型中，否定副词有hardly,not,nowhere,seldom,notonly,scarcely,never,little,atnotime,innocircumstance.Ishallneverdothisagain.NevershallIdothisagain.如：[P184第52、53题]、[P206第48题]、[P230第47题]relieve:解除或减轻(痛苦、忧虑等)relate:relate…to/with…把…和…联系起来retain:保持；保留ignore:忽视；忽略neglect:忽视；忽略refuse:拒绝asfor(sb./sth.):至于Asforyou,youshouldbeashamedofyourself.besides:除了Besidesme,theyallwenttotheSummerPalace.except:除了Exceptme,theyallwenttotheSummerPalace.sufficient:充足的，充分的effective:有效的efficient:有能力的，有效率的respective:各自的，分别的progress:进步，进展proceed:继续前进，继续下去promote:推销propose:建议，计划分词做状语分词或分词短语作状语时，可以表示时间，原因，行为方式，伴随状况等。1.现在分词有一般式和完成式，一般式表示和谓语动词所表示的动作同时发生的行为，完成式表示在谓语动词所表示的动作之前发生的动作。主动被动一般式doingbeing+done完成式having+donehaving+been+doneBeingastudent,Imuststudyhard.(原因)Havingbeenexaminedbythedoctor,thepatientwenthome.注意：当分词的逻辑主语与主句的主语不同时，分词必须有自己的主语。Timepermitting,