情态动词特殊用法

情态动词,特殊用法,表示客观可能性Accidentscanhappenonsuchrainydays.表示猜测（惊讶、怀疑、不相信的态度）CanthisgreenbikebeLiuDongs?构成下列特殊句式：（）cannot/cannevertoo或cannotenough无论怎么也不过分；越越好；非常。Onecannotbetoocareful.越认真越好。Icannotthankyouenough.我对你感激不尽。Youcantpraisehimtoohighly.你怎么表扬他也不过.(他十分出色)（2）cannothelpdoing/cannothelpbutdo/cannnotbutdo”禁不住；不由得；不得不“。IcannothelpadmiringthepicturewheneverIlookatit.Whenaclosefrienddies,youcannotbutfeelsad,Can(could)和beableto,都可以表示能力,意思上没有区别.但can只有现在式和过去式,而beableto则有更多的形式.例如:Nooneisabletodoit.没人能做这件事.Willyoubeabletocometonight?你今晚能来吗?ImsorryIhaventbeenabletoansweryourletter.对不起我一直没能给你回信.Shesaidshehadnotbeenabletocomeearlier.她说她没有能够来得更早一些.但是,在表示成功地完成某一具体动作时,通常不用could,而用was/wereableto来表示.这时,was/wereableto相当于managedto或succeededindoing,表示经过一番努力，终于能够。Theywereabletoputoutthefirewithoutanyhelpfromthefirefighters.,must有“偏要、硬要”之意。Hey,beysMustyoushoutsoloudly?Howoldareyou,madam?Ifyoumustknow,Imtwicemysonsage.表示推测+bedone+bedoingmust+havedone+havebeendone+havebeendoing否定式mustnot(mustnt)表示“禁止”；Youmustnttouchthefire.Mustwefinishtheworktomorrow?No,youneednt(donthaveto),butyoumustfinishitinthreedays.,may句式用来表示祝愿。Mayyousucceed!=Ihopeyoumaysucceed.Mayyoubehappy,healthyandwealthy!may(might)aswell动词原形：不妨做Ifthatisthecase,wemayaswelltry.Nowthattheywereallhere,shemightaswellspeakhermind.,1.b.shall用于第二，第三人称，表示说话人给对方的命令(法律法规的规定），警告，允诺或威胁。在疑问句中，表示征询听话人是否愿意。Youshallhavemyanswertomorrow.(允许)Heshallbesorryforitoneday,Itellyou.(警告)YoushalldoasItellyou.(命令或分咐)Shallyougowithme?(征询意见)2.用于一、三人称的疑问句中，表示说话人征求对方的意见和向对方请示。例如:Shallwebeginourclass?Whenshallmyfatherbeabletoleavehospital?,“Theinterest_bedividedintofiveparts,accordingtotheagreementmadebybothsides,”declared(宣布)thejudge.A.mayB.shouldC.mustD.shallIthasbeenannouncedthatcandidates_remainintheirseatsuntilallthepapershavebeencollected.A.canB.willC.mayD.shall,should表示预测可能性，并译作“可能，(按道理)应该”；Itistenoclock.Theyshouldcomeherenow.(按道理应该到了)表示说话人对已经出现的事态感到“惊奇、惊喜、怀疑”“竟然”ImamazedthatMr.Harrisshouldhavesaidnothingaboutthematter.Why/Howshould结构表示说话人对某事不能理解，感到意外、惊异等意思，意为“竟会”。Whyshouldyoubesolate?你今天来得怎么这么晚？HowshouldIknow?我怎会知道！(意为：我不知道。),will用于各种人称，表示意志或决心。will指现在，would则指过去。Iwilldomybesttohelpyou.我会尽力帮你的。Hesaidthattheywouldhelpus.他说他们会帮助我们的。Ihavetoldhimagainandagaintostopsmoking,buthewillnotlisten.表示习惯性、经常性、倾向性，意为“总是”，“惯于”或“会要”。will指现在，would是指过去。鱼没水就会死。Fishwilldiewithoutwater.星期天当他在北京的时候就会来看我。HewouldcometoseemeonSundaywhenhewasinBeijing.,would与usedto的区别：Wewouldsitintheyardeveryeveningandlistentohisstory.(过去常有的习惯，但言下之意是现在可能还有这样的习惯。)Weusedtositintheyardeveryeveningandlistentohisstory.(过去常有的习惯，但言下之意是现在没有这样的习惯了。)Thereusedtobeaparkhere.,usedto表示过去的某种习惯，现在已经没那样的习惯了；would表示过去有某种习惯，现在可能还有。表示过去的状态，只能用usedto，不能用would。,need既可以用needtobedone也可以使用needdoing，两种形式都表达被动的意义Thehouseneedspainting=thehouseneedstobepainted.Thewatchneededrepairing=thewatchneededtoberepaired.,表示请求或允诺的情态动词(1)向对方提出建议时用：Shall/May/Might/Can/CouldI/we.?Shallhe/she/they.?Would/Willyou.?(2)could/might/would/should表示委婉的语气,肯定回答：用may/can;不用could/might否定回答：用cant/mustnt。Could/MayIuseyourbicycletomorrowmorning?Yes,youcan/may.Shallhecometoseeyou?Ofcourse,please.AndIdratherhetoldmethetruth.,m