Unit 2 Let's celebrate!单元语法（情态动词的用法总结）讲义-高中英语外研版（2019）必修第二册

Unit2Let'scelebrate!-单元语法（情态动词的用法+总结）情态动词的用法情态动词＋动词原形（一）can＋动词原形：1．用于肯定句，表示客观可能性，意为“可能”。-Asahumanbeing,anyonecanmakeamistake.-作为人类，任何人都有可能犯错。2．用于否定句或疑问句，表示对现在的动作或状态进行主观的猜测。-Hecan＇thavealotofmoney.-他不可能有很多钱。-There'ssomeoneoutside-whocanitbe?-外面有人，会是谁呢？（二）may＋动词原形：表示主观的推测，意为“或许”，用于肯定句和否定句均可。-Hemaybeverybusynow.-他现在可能很忙。-Hemaynotbeathome.-他可能不在家。（三）might＋动词原形：表示推测，意为“可能”，可以指过去的情况，也可以指现在的情况，但语气比may更加不肯定。用于肯定句或否定句均可。-TheymighthavealotofworktodonowbutI'mnotsure.-他们现在可能有很多活儿要干，不过我不确定。-Shewasafraidtheymightnotliketheidea.-她担心他们可能不喜欢这个想法。（四）could＋动词原形意为“可能”，可以指过去的情况，也可以指现在的情况，语气缓和。多用于否定句或疑问句。-Helooksyoung.Hecouldn'tbeover50.-他看起来很年轻，不可能超过50岁。-Coulditbetrue？-那可能是真的吗？（五）must＋动词原形表示猜测，意为“准是，一定”，通常用于肯定句。-Thismustbeyourroom.-这一定是你的房间。-Lookathisnewcar.Hemusthavealotofmoney.-瞧他那辆新车。他肯定很有钱。情态动词＋完成式（一）must＋完成式：表示对已发生情况的推测，通常用于肯定句。-Itmusthaverainedlastnight,fortheroadisquitemuddy.-昨晚一定下雨了，因为路很泥泞。（二）can+完成式：表示对已发生情况的推测，主要用于否定句或疑问句。·Youcan＇thaveforgottenher.-你不可能已经忘记她了。·There'snowheretofindthem.Wherecantheyhavegone?-到处找不到他们，他们可能到什么地方去呢？（三）could＋完成式：表示对过去情况的推测，多用于否定句或疑问句。·Hecouldnothavebeenmorethan16atthattime.-他当时不可能超过16岁。-Couldshehaveforgottenmyaddress？-她会忘记我的地址吗？（四）may／might＋完成式：表示对已发生事情的不肯定的推测，might相比may语气更加不肯定。-Hemay／mighthavecomebytrain.-他可能是坐火车来的。单元语法习题练习（一）用方框内情态动词或含情态动词的结构并结合括号内所给词填空： can,can'tdo,may/mightdo,maynotdo,mustdo,musthavedone,can'thavedone,may/mighthavedone1.Someone_____________(set)offfireworkslastnight，becausethegroundisfullofashes.2.Inpolarregions,people___________notseethesunforalongtime. 3.Tom_____________(wear)thatfancydress.Heisalwaysshy. 4.He_____________(be)theeditor.He'sexactlyliketheoneinthispicture. 5.He (finish)thatnovel.Hehasbeenbusytakingcareofhissickchildrecently.6.You______________(think)thatdecoratingthebuildingisawasteofcost,butI'msurelateryouwillbegratefulyoudidit. 7.Thatguy_____________(be)Peter-heisinhospital.8.Thesestudents______________(read)myblog,butI'mnotsure. 答案：1.musthaveset2.can.3.maynotwear4.mustbe5.can'thavefinished6.may/mightthink7.can'tbe8.may/mighthaveread（二）翻译句子：1．他一定正在教室里做练习。（mustbedoing）___________________________________________________________________________.2．他不可能去了上海，刚才我还看见他了。（can’thavedone)__________________________________________________________________________.3．不要吃这些蘑菇，它们可能有毒。（coulddo）__________________________________________________________________________.4．他今天下午可能不来。（mightdo）___________________________________________________________________________.5．屋里很冷，他们一定把暖气关了。（musthavedone）____________________________________________________________________________.6．布朗先生一向准时。这次开幕式他怎么可能迟到呢？(cando)_____________________________________________________________________________.答案：1.Hemustbedoinghisexercisesintheclassroom.2.Hecan'thavegonetoShanghaiforIsawhimaminuteago.3.Don'teatthesemushrooms.Theycouldbepoisonous.4.Hemightnotcomethisafternoon.5.Itiscoldintheroom.Theymusthaveturnedofftheheating.6.Mr.Brownisontimeforeverything.Howcanhebelatefortheopeningceremony?（三）语法填空：Tomwashavingclassintheclassroomwhensomeoneknockedatthedoor.“Who___1_____itbe?It2 betheheadteacher,becauseheisattendingameeting.It__3_____bemymathsteacher.”Hewaslostinthought.Whenthedoorwasopened,Tomfounditwashismother.“You4 havesomethingimportant,soyoucomehere,”Tomsaid.“Yes.Ican'tfindmykeys,andIthinklasttimeyouusedthemyoumay5 (misplace)them,”hismothersaid.Tomexplainedthatit6behim,andshemust7 (be)wrong.“8itbePeter?”Tomasked.“No,Petercan't9 (take)mykeysbecausehisownareinhisbag,”hismotheranswered.Suddenly,hismothersaidinexcitement,“Oh,yes,the