TheFifthPeriodModalVerbs(Ⅰ)TeachingAims:1.Reviewtheusagesofmodalverbswhichexpress“obligation”.2.Sumupsomeothermainusagesofthesemodalverbs.TeachingImportantPoints:1.Howtocorrectlyusemodalverbswhichexpress“obligation”.2.Howdotellthedifferencesbetween“must”and“haveto”andbetween“mustn't”and“don'thaveto”.3.Howtounderstandthemeaningofthestructure“should/oughtto+have+p.p.”.4.Howtocorrectlyusethenegativeformsof“hadbetter”,“oughtto”and“haveto”.TeachingdifficultPoints:Howtocorrectlychoosemodalverbsindifferentsituations.TeachingMethods:1.Reviewmethodandinductivemethodtoenablethestudentstomakeclearwhatthey'velearned.2.Practicetomakethestudentsmasterwhatthey'velearnedcorrectly.TeachingAids:aprojectorandsomeslides;amultimediaTeachingProcedures:StepⅠ.GreetingsGreetthewholeclassasusual.StepⅡ.Lead-inT:Inthesetwounits,welearnedtousesomemodalverbstoexpress“obligationandduty”andtogiveadviceaboutsomething.Pleasetellmewhattheyare?Ss:Theyaremust,have(got)to,hadbetter,shouldandoughtto.(TeacherwritesthemontheBb.)T:Yes.Nowlet'sdoanexercise.(Teachershowsthescreen.)1.Whentravelling,you__________takecareofyourhealth.2.Insomepartsoftheworld,you__________boilthewaterbeforedrinkingit.3.Ifyouhaveastomachpain,you__________drinkhotweaktea.4.You__________takethismedicine,butyourheadmayhurtlessifyoudoso.5.You__________swimimmediatlyafteraheavymeal.6.You__________notwakemeupwhenyoucomein.Nowlookatthesentencesonthescreenandfillineachblankwiththemodalverbsontheblackboard.Let'sfinishthemtogetherorally.Suggestedanswers:1.should/must2.must/haveto3.should/oughtto4.don'thaveto5.shouldnot/oughtnotto/mustnot6.hadbetter用心爱心专心StepⅢ.RevisionoftheUsagesoftheModalVerbsT:Welldone.Asweallknow,“must,shouldandoughtto”allexpressobligationandduty.When“must”expressesobligationandduty,itismuchmoreforcefulthan“should”and“oughtto”.Itexpressesveryemphaticadvice.Forexample:Theworkmustbefinishedbeforedark.“Must”isonlyusedinaffirmativesentenceandaninterrogativesentencetoexpressobligationandduty.Thenwhatshouldweuseinanegativesentence?Ss:Don'thaveto,needn'tordon'tneedto.T:Whydon'tweuse“mustn't”?Ss:“Mustn't”expresses“beforbidden”.(Bb:must,don'thaveto,needn't,mustn't)T:Nowpleaselookattheexerciseonthescreenandchoosethebestanswer.(Teachershowsthescreen.)—MustIdoitnow?—No,you__________.A.needn'tB.don'thavetoC.mustn'tD.AorBSs:D.T:Yes.ItisD.Wecan'tuse“mustn't”toexpressobligationandduty.Areyouclearaboutthat?Ss:Yes.T:Doyouknowthedifferencebetween“must”and“haveto”?S1:Yes.“Must”expressesanobligationimposedbythespeaker,while“haveto”expressesanexternalobligation.S2:Besides,“haveto”canbeusedinalltenses,while“must”canonlybeusedtoexpressthepresenttenseandthefuturetense.T:Thenhowaboutthedifferencebetween“haveto”and“havegotto”?S3IninformalEnglish,“havegotto”isusedinsteadof“haveto”.T:Quiteright.Nowpleaselookatthesentencesonthescreen.(Teacherusesmultimediatoshowthesentencesonthescreenandstudythemwiththestudents.)1.Thatboyhastopractisethepianoeveryday.2.Youwillhavetokeepyourdogonaleadwhenyouaretravelling.3.HelostallhismoneyandIhadtolendhim$5.4.Childrenmustobeytheirparents.5.Imustgohometolookaftermymother.(Bb:hasto,willhaveto,hadto,must.)T:OK.“Must”canalsoexpress“guess”whenwewanttosaythatwearesureaboutsomething.“Must”isonlyusedinthiswayinaffirmativesentences.Inquestionsandnegatives...
