搜索
Firstwealthishealth.Q1:Whatshould/shouldn’twedotokeephealthy?Q2:Whatkindoffoodmustweeattobestrong?Q3:Whatoughtwetoeattostayslim?主要情态动词•Can,could•May,might•Must/haveto•Need•Dare•Will/would•Shall/should/oughttoWhatmodalverbshaveyoulearned?1.情态动词有一定的意义，但是不能独立使用，它和后面的动词构成谓语。2.没有人称和数的变化，即情态动词第三人称单数不加-s。3.情态动词除ought和have外，后面只能接动词原形4.情态动词没有非谓语形式，即没有不定式，分词等形式。只作情态动词的can/could,may/might,oughtto,must可情态可实义的need,dare可情态可助动词的shall/should,will/would相当于情态动词的haveto情态动词的语法特征•a.Bylunchtimetheywouldhaveallbesold---•b.Hisrestaurantoughttobefullofpeople.---•c.Nothingcouldhavebeenbetter.---.•d.SomethingterriblemusthavehappenedifLiChangwasnotcomingtoeatwithhimashealwaysdid.---•e.Hewonderifheshouldgotothelibrarytofindout---•f.Hewouldn’thaveYongHuigettingawaywithtellingpeoplelies!---possibilitypossibilitypossibilityguessingdutyintention情态动词含义否定式注意点must表必要“必须”needn’t“不必”(区别haveto)有时表“偏要”表推测“一定”can’t“不可能”只能用于肯定句，不能用于否定、疑问句1.must&need&haveto注意：must表示推测时，只能用于肯定句。mustdo对一般时的肯定推测musthavedone对过去发生的事情作出的肯定判断mustbedoing对现在的动作进行肯定推测e.g.他们买了一辆新车。他们一定很有钱Theyhaveboughtanewcar.Theymusthavealotofmoney.他现在一定在看小说Hemustbereadingnovelsnow.路是湿的。昨天晚上一定下雨了。Theroadiswet.Itmusthaverainedlastnight.---Needhestartfromthebeginning?---Yes,hemust.---No,heneedn’t/doesn’thaveto.1.作情态动词时,仅用于否定或疑问句,后接动词原形,表“需要”2)needYouneedn’treturnthebooknow.2.needn’thavedone表示做了本不必要做的事情,意为“本不必要…”OurcolorTVsetisstillgoodenough.Youneedn’thaveboughtanewone.3.作实义动词时,表示“需要”，有人称、时态、和数的变化Heneedstofinishitthisevening.Theclassroomneedscleaning.注意对need问句的回答:--NeedIfinishtheworktoday?--Yes,________________.No,________________.No,________________.youmustyouneedn’tyoudon’thavetoneedn’t对其它情态动词的回答:--ShallItellJohnaboutit?--No,you__________.--No,you__________.--Mustwedoitnow?--No,you__________.--No,you__________.needn’tdon’thavetoneedn’tdon’thaveto情态动词含义否定式注意点can/could表能力“能/会”can’t“不会，不能”区别beableto表许可“可以”can’t“不可以，不许”代替may表推测“可能”can’t“不可能”主要用于否定/疑问句中1表示某人通过努力克服困难做成某事,要用was/wereableto.2could,might,would表委婉语气用于疑问句,答语仍须用can,may,will.3can用于肯定句中,可表示”有时可能”2.can/could4.can/couldhavedone“本可以，本可能做某事”用于肯定句中，表示对过去发生的事情做出的判断。你本来可以考的更好。Youcouldhavehadabettermark.5.can/couldnothavedone对过去发生行为进行推测:不可能做某事1)刚才我还看见他了，所以他不可能出国的。Isawhimjustnowsohecouldn’thavegoneabroad.2)门是锁着的，所以她不可能在家。Thedoorwaslocked，soshecouldn’thavebeenathome.情态动词含义否定式注意点may/might表许可“可以”mustn’t“不许，严禁”口语中也可用can’t表推测“可能”can’t“不可能”主要用于肯定句，不能用在疑问句（maynot可能不）3.may/might注意：might/mayhavedone,表示对过去发生的动作进行可能性推测，1）他可能去医务室了。Hemayhavegonetotheclinic.2）他可能已经从报纸上知道这个消息了。Hemighthavereadaboutthenewsinthenewspaper.1.---MayIuseyourpencil?---Yes,youmay./No,youmustn’t.2.Shemaybeworkingnow.3.Helenmaygoonthetripwithus,butsheisn’tverysureyet.4.Shemay/mighthavereaditinthepaper.情态动词用法will表请求(第二人称)表意志,意愿表某种倾向或习惯would更客气的请求过去的意志（愿）过去的倾向或习惯4.will/would情态动词用法shall征求对方意见(第一,三人称)表示命令,警告,威胁或允诺(第二,三人称)should/oughtto表示劝告,建议,命令或责任“应该,必须”表示推测,“理应,估计,大概,可望”should还可表示“竟然”5.shall,should和oughttoYoushalldoasIsay.(命令)1.在陈述句中,shall用于二、三人称表示允诺、警告、命令、决心等。ShallIopenthewindowforyou？（征求意见）2.在疑问句中,用于一、三人称，用来表示请求或征求意见。注意：Tellhimthatheshallhavethebooktomorrow.(允诺)Nothingshallstopmedoingit.(决心)Shallhefetchsomewaterforyou？（请求）Youngpeopleshouldlearnhowtousecomputers.3.should常表示劝告、建议、命令，与oughtto意义相近，但oughtto多表示责任、义务，语气强烈。Everycitizenoughttoobeylaw.Yououghtnottogo.Youshould/oughttohavetoldherthetruthearlier.Sheshouldn’thaveleftwithoutsayingaword.4.should/oughttohavedone表示责备或批评,意为“本应该…但”,oughtto的语气更强烈,用于否定则表示“本不该…但”5.Should用于可能性推测时,表“应该，很可能”Theyleftat5:30.Theyshouldgettherenow.1.作为情态动词用，常用在否定句和疑问句中。Dare(need)+S+VS+daren’t(needn’t)+VIdaren’twalkthroughtheforestatnight.Dareyouwalkthroughtheforestatnight?Youneedn’treturnthebooknow.Needhegoyesterday?6.可兼做行为动词的情态动词：need、dare判断正误:Howdareyousaysuchathing?Howdareyoutosaysuchathing?Hedaren’ttospeakEnglishbeforesuchacrowd,didhe?Hedaren’tspeakEnglishbeforesuchacrowd,darehe?Nobodyneedtobeafraidofcatchingthedisease.Nobodyneedbeafraidofcatchingthedisease.2.作实义动词用，常用在肯定句中,有人称、时态、和数的变化Heneedstogotherehimself.Hehasgrownup,sowedon’tneedtoworryabouthim.3.Sth(sb)need(want,request)+doing/tobedoneThehouseneedscleaning/tobecleanedTheboyneedssendingtothehospitalatonce.表示推测——情态动词的重要用法肯定的推测可能的推测否定的推测疑问的推测must对将来对现在对过去情态动词may,mightcan’t,couldn’tcan,could+V.+V.+havedone常见mustbe+bedoing+V.+V.+havedone+bedoing可以用not表示“可能不”+V.+V.+havedone+bedoing+V.+V.+havedone+bedoing用情态动词完成句子1).You’vebeenworkingallday.You______beverytired.2).(Thedoorbellrings)Iwonderwhothatis.It______beLisa.She’sstillinthelibraryatthistime.3).Itisalongtimesincewemetlasttime.You______comeandseeusmoreoften.mustcan’tshould4.Ihaven’tdecidedwhereI’mgoingformyholidays.I_____gotoAustralia.5.Myfather’sbirthdayisccoming.What_____Igivehim?6.Whydon’tyoutryonthisdress?It_____lookniceonyou.mayshallwill7.“Whowasthemantalkingwithyourteacher?”“I’mnotsure.It______beherbrother.”8.Idon’tknowwhentheguests_____behere.They______arriveatanytime.mightwillcould3.完成下列句子：1.Idon’tknowwheresheis,she_______________.(可能在武汉）(be)2.Atthismoment,ourteacher_______________（想必在批改）ourexampapers.(mark/grade)3.Theroadiswet.It________________(一定下雨了）las