情态动词在英文中主要用来表示说话人的看法、态度等。它很接近中文里的能愿动词。从用法上来说，它有这样几个特点：1）各个情态动词自身都有一定的词义。2）情态动词不能在句中独立担当谓语。3）情态动词在句中不受任何人称,性,数变化的影响。4)情态动词后接的不定式（除ought外）都不带to，即接动词原形cancould表示脑力或体力上的能力ShecansingthatsonginEnglish.2)表示客观上的可能性(有时会）sometimesattimesNowpeoplecanskateonthelake.3)表示主观上的允许CanIaskyousomequestionsaboutit?YoucannotleaveheretillIcomeback.直到我回来你才能离开。4）（用于否定句、疑问句或感叹句中）表示猜测、怀疑或惊诧Howcan/couldyoubehere?你怎么会在这儿？Shecouldn't/can'tbesostupidtodothatcan’t/couldn’t„too„再„„都不为过比较级肯定意义非常Youcan’tdrivetoofastItcan’tbebetterPeter______bereallydifficultattimeseventhoughhe’sanicepersoningeneral.(2008辽宁)A.ShallB.shouldC.canD.mustWeusuallyhaveawarmwinterhere,thoughit_____coldsometimes.A.mustB.shouldC.shallD.canmay,might,1）可能性Imaybebusyfromtomorrowon.Shethoughtitmightbewisetotryherluckhere.2）表示允许MayIcomein?3)may间或用来表示祝愿，也常用于表示目的或让步的状语从句中:Maythatdaycomesoon.Mayyousucceedinwinningthefirstprizeinthegame.4)may\mightaswell+doIfthatisthecase,Imayaswelltry.Whatyousaymaywellbetrue.你说的很可能是事实IgotcloseenoughtohearthemspeakingChinese,andIsaid“NiHao”justasIdoinChina.A.mustB.mightC.havetoD.shouldshallIshallbethirtynextyear.明年我就三十岁了。2.征求对方意见,主要用于第一、第三人称)...好吗?要不要...?Shallwebeginnow?用于陈述句中的第二、第三人称,表示说话人的意图、允诺、警告、命令、决心等)必须,应,可Youshallhaveitbacknextweek.下星期一定还你。4.(用在条约、规章、法令等文件中表示义务或规定,一般用于第三人称)按规定Intrudersshallbepunished.1、*(2011陕西)---willyoureadmeastory,Mummy?-Ok.You______haveoneifyougotobedassoonaspossible.A.mightB.mustC.couldD.shall2、*Accordingtotheschoolrules,nostudent______gooutoftheschoolaftereleveno’clockatnightwithouttheteacher’spermission.A.willB.mustC.shallD.may3.*Imayletyougetawaywithyourbadbehaviorthistime,butImustwarnyouthatifthishappensagain,you______bepunished.A.willB.shallC.canD.Must4Theresearchonthenewbirdfluvirusvaccine(疫苗)ischallenginganddemanding.Whodoyouthinkcandothisjob?-__________mystudentshaveatry?A.ShallB.MustC.WillD.May5*Sir,aMr.Smithiswaitingtoseeyououtside.______hecomeinorstaythere?A.WillB.MayC.ShallD.MustShould■表示“应该，应当”Y