深圳牛津英语 7B unit 6 Grammar(情态动词)

7Bunit6GrammarModalverbscanandcannotmayandmaynotmustandmustnotModalverbs情态动词•情态动词本身有一定的词义，但需要与动词原形一起使用，给谓语动词增添情态色彩，表示说话人对有关行为或事物的态度和看法，认为其可能、应该或必要等。•情态动词后面通常加动词原形。本单元我们要具体学习的是can,may和must这三个情态动词。Grammar:ModalverbsIcanspellallthewordswehavelearnt.Canyoudothat?Acanandcannotcanandcannot•我们用can表示某人具备某种能力做某事。此时可用beableto代替。如：•Icanplaybasketball.我会打篮球。•=Iamabletoplaybasketball.•当表示“经过努力才得以做成功某事”时应用beableto，不能用can。如：Hewasabletogotothepartyyesterdayeveninginspiteoftheheavyrain.can的过去式为could,could表示过去的能力.如：Hecouldruntenyearsago.十年前他还可以跑步。•can的否定形式为cannot或can't.如：•Icannotswim.我不会游泳。•疑问句中，把can提到句首，将can与主语的位置对调。•Canyouspeakanyforeignlanguages?•你会说外语吗？•肯定回答：Yes,Ican.否定回答：No,Ican't.GametimeWhatcanyoudo?Tellthestudentbehindyouandaskifhe/shecandoit.Thenextstudentshouldrepeatthiswithanotherstudent.Example:No,Ican’t.Icansing.Canyousing?Yes,Ican.Ican…Canyou…?Icanswim.Canyouswim?GrammarexercisecancannotcannotcancannotcancancannotYouwillbegivenseveralsituations.Afterreadingthedescriptionsandlookingatthepictures,decidewhatyouwouldsayinthesesituations.a.Amanisgoingtoseehisboss.Heisstandingatthedoorway.MayIcomein?b.Astudentisgoingtoasktheteacheraquestion.MayIaskyouaquestion?c.Aboyisthirsty.Heisaskinghismotherforsomething.MayIhavesomewater?d.Ashopassistantisservingacustomer.MayIhelpyou?Weusemayandmaynottoaskforandgivepermission.Inlessformalsituations,somepeopleliketousecanandcannot(can’t)forthesamepurpose.“May”canbeinterchangedwith“can”,butit’salittlemorepolitetouse“may”.Bmayandmaynotmayandmaynot•在请求对方的许可，或是准许你做某事是，常用情态动词may和can。may(否定形式为maynot,没有缩写形式)比较正式，can较常用且更口语化一些。•如：•---MayIleaveworkearlytoday?•---Yes,youmay./No,youmaynot.•---CanIopenawindow?•---Yes,youcan./No,youcan't.•Youmay/canusemybike.•Youmaynot/cannotusemycomputer.GrammarexerciseMay/CanMaycanMayCanCmustandmustnotWhatdothesesignsmean?（Youmustn’tsmokehere.）（Youmustn’tclimbthisladder.）（Youmustn’tswimhere.）（Youmustn’tuseyourmobilephonehere.）mustandmustnot•must用以表示“必须做某事”或“一定要做某事”，具有强制性，表达一种责任或义务或表示很有必要做某事；或在提出建议时使用，意为“应该，得”。•Wemustobeytheschoolrules.•我们必须遵守校纪校规。•Thewindowsareverydirty.Imustcleanthe•窗子很脏，我必须擦一擦了。•Wemusttotothebanktoday.Wehaven'tgotanymoney.•我们今天一定要去银行了我们一点钱都没有了。must的否定形式为mustn't(=mustnot),表示“禁止，绝不允许”，具有强制性如：Imusthurry.Imustn'tbelate.我必须要快点，我绝对不能迟到。Youmustn'tforgettophoneTom.你绝对不能忘记给汤姆打电话。must“必须”don’thavetoneedn’tdodon’tneedto2.must还可表示“偏偏、偏要”e.g.Mustyoumakesomuchnoise?你偏要弄出这么多噪音吗？1.不必须mustn’t禁止Imustgotobedearly.Imusttakethemedicineontime.eatcoldfoodImustnotgooutalone.Imustnotsharecupswithothers.由must引出的一般疑问句，肯定回答用must,否定答语用needn't或don'thaveto。如：•—MustIdotheworknow?•我必须现在干这个活吗？•—Yes,youmust/haveto.•---No,youneedn't/don'thaveto.①mustbe——“肯定推测”e.g.---WhatisTom?---Hemustbeastudent.②“否定推测”——can’tbee.g.---WhereisTom?---Hecan’tbeinthelibrary.◆拓展(推测,可能)·Heisintheclassroom.100%·must﹥99%(must表推测，用于肯定句)e.g.Hemustbeintheclassroom.他肯定在教室。·may50%(may表推测，用于肯定句)e.g.Hemaybeintheclassroom.他可能在教室。·can’t/couldn’t(can/could表推测用于否定句)e.g.Hecan’tbeintheclassroom.他不可能在教室。must必须—表示说话人的主观看法haveto不得不—表示外界客观愿望，即“不得不”。e.g.Theheadteachergivesussuchanimportantworktodo.Wemustdoourbest.e.g.Mymotheriscallingme.Ihavetogo.◆拓展（must与haveto的区别）can—用于一般现在（can）、一般过去时态（could）。beableto—用于一般现在（amableto）、一般过去时态（was/wereableto）、一般将来时态（willbeableto）。◆拓展（can与beableto的区别）•Homework:•完成BookBGrammarP96----98的练习。