情态动词用法归纳

情态动词用法归纳一shall和will的用法1、shall用在第一、三人称，will用于第二人称表示“征求意见”。ShallIgonow?Shallweinviteher,too?Willyouhelpmewiththework?Shallthereporterswaitoutsideorwhat?2、shall表示依据规定有义务去做。Passengersshallnottalkwiththedriverwhilethebusismoving.3、shall用于所有人称，表示说话人的许诺、威胁、警告、命令等。Youshallhaveananswerbytomorrow.Ifhesgood,heshallhaveanewwatchforChristmas.IfyouchildrendontdoasItellyou,youshantgototheparty.4、would可以表示过去的习惯（would可表示反复发生的动作或某种倾向。usedto表示过去的习惯动作或状态，强调现在已不存在）HewouldcometoseemeonSundaywhenhewashere.Thedogwouldliethereinthesunallafternoon.Whenwewerechildren,wewouldgoskatingeverywinter.5、will可以表示“愿意”，而非将来:Iwillpayyouforit.Gowhereyouwill.Weregoingonaclimbingtrip.Comeifyouwill.6、will可以表示倾向、习惯（总是会，老是等意思）Sometimesthecatwillliethereallmorning.Oilandwaterwillnotmix.Thismachinewontwork.二、can/could的用法1、表示具备某种能力。Thenine-yearoldboycanswimacrosstheriver.Canyouswimacrosstheriver?Wecouldntgetthetrucktostart.2、表示“征询对方意见”和“允许”（could语气委婉）。回答不用could.Can/couldIsmokehere?Yes,youcan.No,youcannot.CouldyoutellmewhereJohnis?3、表示“可能性”。（否定句疑问句常见,肯定句也可以）Can/Coulditbetrue? 那会/可能是真的。Thatcant/couldntbetrue. 那不可能是真的。Willyouanswerthephone?Itcouldbeyourmother.三may/might的用法1、表示“征询对方意见”和“允许”。MayIturnontheTV?Yes,ofcourse.Yes,youcan/may.No,youcant/maynot/mustnt/Imafraidnot.Youmaygohomenow.2、表示可能性，“也许”。常用于肯定句。Youmay/mighthavesomefever.你也许发烧了。Hesaidthatthenewsmightbetrue.他说这消息可能是真的。Theymay/mightbehavingabath.他们也许正在洗澡。四must的用法1、表示“必须Patientsmustusemedicineaccordingtothedoctorsorders.2、表示推测，只用于肯定句。在否定句或疑问句中，用can/could：Theremustbeamistake.Can/CouldtherebeamistakeTherecant/couldntbeamistake.3、注意must的回答：Musttheladiesweardresses?yes,theymust.No,theydonthaveto./theyneednt.Can/MayIcomein?No,youcant/mustnt.4表示禁止。Childrenmustntgoacrossthestreetalone.五表示“推测”的表达法总结（1）表示对现在和将来状况的推测：must一定，may可能，might也许，cant不可能。（2）对已经过去的情况的推测，用“情态动词have+done”结构：musthavedone 过去一定已经（只用于肯定句中）cant/couldnthavedone 过去不可能-（表示否定）may/mighthavedone 可能已经-neednthavedone 本来不必做-couldhavedone 那时本来可以（在肯定句中，不可用can)shouldhavedone 本来应该做-（实际未做）shouldnt/oughtnttohavedone 本不应该做-（实际做了）Hemusthavebeendrinkingbeer.他肯定一直喝啤酒来着。Themoneycanthavebeenlostthere.钱不可能是在那儿丢的。Hemayhavegonetobed.他可能已经上床睡觉了。Shemightnothavesettledtheproblem.她可能尚未解决那个问题。Wecouldhavesolvedtheprobleminamorereasonablefashion.Youshouldhavecomeheretenminutesearlier.Sheshould/oughttohavegonetherealone.六、need的用法1、作为情态动词，need一般只用于否定句和疑问句中。Youneednttrytoexplain.Needwestayherethisevening?2、Need作为实意动词可用在所有句型中。Sheneedstocometomorrow.Youdontneedanyhelpfromothers.Dotheyneedthis?七、dare的用法1做情态动词，通常用于疑问句，否定句和条件状语从句中。Dareheswimacrosstheriver?Hedarenotcometoseeme.Howdareyoubesorude!你竟敢如此无礼！2做实意动词：Doyoudaretoaskher?你敢问她吗？Hedidntdaretogo.他不敢去。八should/oughtto的用法两者大多数情况下可以互换。1、表示道义上的责任，义务或要求，有时表示劝告。Yououghtto/shouldpaymoreattentiontowhatyourlawyersays.Thiswordisspeltwrongly.Thereshouldbeanother“s”.2.表示推测和可能性，是“应该”之意。Thispenoughtto/shouldbeyours.这支笔应该是你的。Ifthetrainisuptotime,Johnshould/oughttobehereanyminutenow.如果火车晚点的话，John现在马上就应该到了。3、表示讲话人惊奇，失望，愤怒等感情：Whatshappenedt