高一英语情态动词1.can(1.)能力HecanspeakfluentEnglish.区别can与beableto的用法:①can只有一般现在时与一般过去时;beableto有各种时态②beableto表示经过努力设法做成某事,相当于managetodo/succeedindoingEveryonewasabletoescapefromtheburningbuilding.(2.)客观可能性(肯定句)“有时会”Itcanbequietcoldhereatnight.(3.)请求许可could(委婉语气)CanIhavealookatyournewpen?--CouldIuseyourcomputertomorrow?--Yes,youcan./No,I’mafraidnot.(4.)用在否定句、疑问句中表怀疑,惊讶等Canitbetrue?Howcanyoubesocrazy?can’thelpdoingsth.忍不住做某事,情不自禁做某事Ican’thelpthinkingheknowsmorethanhehastoldus.cannot/never…too再…也不为过,越…越好Youcannotbetoocarefulwhenyoudriveacar.2.may(1.)请求许可might(委婉语气)--MayIsmokehere?--Yes,youmay./No,youmustn’t.(2.)可能性Johnisabsent.Hemaybeill.Itmaybenottrue./Itcan’tbetrue.(3.)用于祈使句中表祝愿Mayyousucceed!may/mightaswell(dosth.)做某事倒也无妨,只好做某事Ifnooneelsewantsit,wemightaswellgiveittohim.maywelldosth.完全可能Theymaywellwin.3.must(1.)必须Soldiersmustobeyorders.区别must与haveto的用法:①must表示主观看法,haveto表示客观需要IfeelImustcallyoutothankyouforyourhelp.It’srainingheavily.Youhavetotakeanumbrella.②must无时态变化,haveto的时态随have的变化③否定形式的含义不同:mustn’t表示禁止,don’thaveto表示不必Youmustn’ttakethebookoutofthereadingroom.Youdon’thavetotellhimthetruthifyoudon’twantto.④回答must问句--Mustwehandinourexercisebooktoday?--Yes,youmust./No,youdon’thaveto/needn’t.(2.)偏偏,偏要Mustyoushoutsoloudly?Ifyoumust(dosth.)(表示虽不赞同但可允许)如果你一定要做某事1--MayIsmokehere?--Ifyoumust,chooseaseatinthesmokingsection.归纳:can,could,may,might,must都可以表推测肯定句→must,may,might否定句→can’t,couldn’t(不可能),maynot(可能不)疑问句→can,could情态动词+do/be表现在情态动词+bedoing表现在进行、将来情态动词+havedone表过去如何运用在反意疑问句中:反意疑问部分中的助动词必须根据陈述句中去掉表推测的情态动词,改为陈述客观事实的陈述句中的谓语动词来判断(可根据时间状语)。(1.)Hemayknowtheplan,________________?(2.)Hemusthavelivedhereforalongtime,____________________?(3.)Hecan’thaveleftyesterday,___________________?4.shall(1.)用于一、三人称,表征求对方意见Henryiswaitingoutside.Shallhecomein,sir?(2.)用于二、三人称,表说话者对主语的命令、规定、允诺、威胁、决心等Thestudentsshallwearuniforms.Youshallgetananswerfrommetomorrow.5.should(1.)应该,表示劝告、建议,相当于oughtto(语气稍强,客观情况)Asstudents,weshouldworkhard.Everycitizenoughttoobeythelaw.(2.)按道理应当Therearemanyhotelsthere.Thereshouldn’tbeanydifficultiesforyoutofindone.(3.)用于表示感情的形容词后的that从句中表竟然Itisastonishingthatheshouldbesorudetoyou.(4.)在why,how,who,what+shouldsb.do结构中表惊讶,恼怒等WhyshouldIhelphim?He’sneverdoneanythingforme.(5.)(表示可能)万一,假如Thecompanyguaranteedfreeafter-salesservice,shouldtheirproductshaveanyriskinsafety.Ifyoushouldchangeyourmind,doletmeknow.6.will(1.)意愿(现在)would(过去)Ifyouwilllistentome,I’llgiveyousomeadvice.Theywouldn’tlethiminbecausehewaspoorlydressed.(2.)用于第二人称,表请求would(委婉语气)Will/Wouldyoupleasepassmethebook?(3.)习惯性动作(现在)would(过去)Fishwilldiewithoutwater.Whenweworkedinthesameoffice,wewouldoftenhavecoffeetogether.区别would与usedtodo/be的用法:would表示过去反复发生的动作,与现在无关;usedtodo/be表示过去的状态,强调现在与过去的对比。2Heusedtobeanaughtyboy.Whenhewasyoung,hewouldsmo...