高中英语 Unit3 Grammar课件 牛津译林版必修3 课件VIP免费

Unit3BacktothepastGrammarPresentperfecttenseGooverthenewsstoryonPage2andfindthesentencesusingthepresentperfecttense.Pleaseexplainwhythetenseisusedinthesesentences.ThedisappearanceofJustin(make)Kellyveryunhappy.hasmade•Weusethepresentperfecttensetotalkaboutthingsthathappenedintherecentpast,butareconnectedtothepresent.TheusesofthepresentperfecttenseI(notsee)JustinsincelastFridaynight.havenotseenWealsousethepresentperfecttensetotalkaboutsomethingthatstartedinthepast,andisstillhappeningnow.Completethefollowingsentenceswiththepropertense.1We(study)Englishforaboutfiveyears.2They(live)inthesouthsincetheirdaughterwasborn.3I(read)yourarticlethreetimes.It’swellwritten.4Thestudent(finish)herhomeworkalready.5Eric(go)backtohishometowntoday.6Thepolice(justfinish)searchingthearea.havestudiedhavelivedhavereadhasfinishedhasgonehavejustfinishedWeusethepresentperfecttensewhentheexacttimeofanactionisnotclearorimportant.Weuseitwithtimeexpressionssuchas:alreadyeverforjustlatelyneverrecentlysinceyetalready,yet;for,sinceWeusealreadyforaffirmativestatementsandyetfornegativestatements.Weusefor+aperiodoftimeandsince+apointintime.Hehasjustgoneout.(=Hewentoutafewminutesago.)Weusethepresentperfecttenseheretotellothersthatheisn’therenow.Ihavejustheardthenews.(NowIknowthenews.)Weusethepresentperfecttensetotalkaboutactionsthatwerecompletedonlyashorttimeago.Inthiscase,justisused.Payattentiontothepositionofjust.Wecanalsousethepresentperfecttenseforrepeatedactions,thatis,weusethepresentperfecttensewiththetimeexpressionsonce/twice/threetimes…Tomhasrungupthreetimesthismorning.(Nowitisstillinthemorning.)Tomrangupthreetimesthismorning.(Nowitisnotstillinthemorning.)Actionsoccurringinanincompleteperiodmightbeindicatedbytodayorthismorning/afternoon/evening/week/month/year/centuryorallday/night/week,allthetime,alwaysetc.Lookatthefollowingsentencesandpointoutwhattenseortensesareusedinthemandthereasonswhytheyareused.1WehavestudiedEnglishforaboutfiveyears.Webegantostudyitfiveyearsago.2Theymovedtothesouthin1990andhavelivedtheresincethen.3Ericlefthomelastyearandhasjustcomeback.4Justinhasbeenawayfromhomeforseveraldays.HedisappearedlastFriday.5Theyboughtthishousethreeyearsagoandtheyhavelivedheresincethen.6Mybrotherwenttoseemygrandpalastweek.Hehasvisitedhimthreetimesthismonth.Thepresentperfecttenseandthepastsimpletense1‘youmypen?’‘Yes,Iitonyourdeskjustnow.’(see)2‘youdinner?’‘Yes,IitwithMary.’(have)3thepostmanyetthismorning?Didthepostmancomethismorning?(come)5Ihimforalongtime.Hello!I(not)youwerehereinNanjing.Howlonghaveyoubeenhere?(know)HaveseensawHavehadhadHavecomehaveknowndidn’tknowThepresentperfecttenseisnormallyusedforanactionwhichlaststhroughoutanincompleteperiod,butwiththepastsimpletense,weusetimeexpressionswhichafixedpointinthepast.c.f.Wehaven’tseenJustinforaweek.(Heisstillmissing.)Justindisappearedlastweek.(ItmaymeanthatthisweekJustinishere.)Hehassmokedsinceheleftschool.(Hestillsmokes.)Hesmokedforsixmonths.(Itmeansthathestoppedsmokingthen.Sometimes,however,theactionfinishesatthetimeofspeaking.Ithasbeenverycoldlatelybutit’sjustbeginningtogetwarmer.Onmeetingsomeone,youmaysay:Ihaven’tseenyouforages.(ButIseeyounow.)Forapastactionwhosetimeisnotdefiniteandoftenhasaresultinthepresent.1Tomhashadabadcarcrash.(He’sprobablystil...