牛津译林版八年级英语上册Unit4Grammarppt课件.ppt

GrammarA1.祈使句的概念祈使句表示请求、命令等。它的主语是you（听话人），通常不说出。祈使句肯定结构中的谓语动词一律用动词原形。祈使句末用感叹号或句号，句子用降调。2.祈使句的结构1)祈使句的肯定结构V 型（以行为动词原形开头），例如：Sitdown!坐下！Standup!起立！Be 型（以be开头），例如：Bequiet!安静！Becareful！小心！Let 型（以let 开头），例如：Letmetry.让我试试看。Letslookatthemap.让我们看看地图。lets 是letus的简略式。表示请求、劝告的祈使句还常常在句前或句末加上please,构成句式：Please或,please.以使语气更加缓和或客气。例如：Pleasestandup.或Standup,please.请站起来。Pleasehavearest.或Havearest,please.请休息一下。2)祈使句的否定结构，一律在肯定结构前加Donot(Dont)。例如：Dontgothere,please.请别去那儿。Dontbelateforclass!上课别迟到！Dontlethimin.不要让他进来。注意：Lets 型祈使句，其否定式也可用Letsnot，例如：Letsnothaverest.咱们别休息了。Letsnotsithere!我们不要坐在这儿！What should we do in the library?Keepthelibraryquiet.Keepthelibraryclean.Readthebookscarefully.KeepthebookscleanWhat shouldnt we do in the library?Dontmakemuchnoise.Dontwriteonthebooks.Donttalktoyourclassmatesloudly.Donttakethebooksoutofthelibrary.GivinginstructionsWestartasentence(句子)withthebaseformofaverbwhenwewanttotellpeoplewhattodo.e.g.Putupapictureonthewall.Paintthewallsblue.Weoftenaddpleaseinasentencetomakeaninstructionmorepolite.e.g.Pleasefixtheshelfforme.Donttouchthewetpaint,please.e.g.Dontpaintthecat.Weoftenadddonot/dontinfrontofaverbwhenwewanttotellpeoplenottodosomething.Millieisteachingherclassmateshowtomakecardstohelpthemrememberthingsbetter.LookatthepicturesandhelpMilliecompletetheinstruction.Howtomakecards_ out pieces of card with a pair of scissors.Cutcutdrawgivekeeplooktrywrite_ some words or a sentence on each card.Writecutdrawgivekeeplooktrywrite_ a picture about the words or sentence on the other side of the card.Drawcutdrawgivekeeplooktrywrite_ at the picture and _ to remember what is on the other side.Look trycutdrawgivekeeplooktrywritePlease _(not)up._ trying,and you will find you can remember things better.dontgive KeepcutdrawgivekeeplooktrywriteHowtobuildabrickhouse?_somebricks(砖块)._thewallswiththebricks._thewindowsandthedoors._surethehouseissafe.FindBuildFixMakefixbuildmakefindParkyourbikehere.Pleasegoslowly.Bequiet,please.Dontmakeanynoise.Dontswimhere.Dontparkyourbikehere.Dontsmokehere.Dontfishhere.1.剪出2.写一些话或一个句子3.在每张卡上4.在卡的另一面5.尝试做某事6.记住某事7.放弃8.放弃某事/做某事9.坚持尝试10.把事情记得更好cutoutwritesomewordsorasentenceoneachcardontheothersideofthecardtrytodosth.remembersth.giveupgiveupsth./doingsth.keeptryingrememberthingsbetterUseful ExpressionsGrammarB当我们给他人提建议时，可以用hadbetter 和should，表示“最好”或“应该”做某事，hadbetter 的语气比should 强一些。Youhadbetterrefrigeratethebeerbeforedrinkingit.喝啤酒前你最好先把它冷冻一下。Youshouldexercisemore.你应该多锻炼。hadbetter(常简略为dbetter)，是一固定词组，后面必须跟动词原形，没有人称和数的变化。构成：hadbetterdosth.句型。Youdbettergotohospitalatonce.你最好立即去医院看病。Tom,youdbettergotheretoday.汤姆，你最好今天去那儿。hadbetter 的否定式是将not 直接放在hadbetter 的后面。Youhadbetternotmissthelastbus.你最好不要错过末班公共汽车。should 后面也要跟动词原形，且没有人称和数的变化。Youshouldstopsmoking.你应该戒烟。should 的否定式是shouldnot/shouldnt。Youshouldntdrinkanddrive.你不应该喝酒后开车。UsingshouldandhadbetterWeuseshouldandhadbetterwhengivingadviceandtellingpeoplewhatwethinkisthebestorrightthingtodo.Thetoneofhadbetterisstrongerthanshould.e.g.YoushouldknowalittleaboutDIY.Youshouldnotputsomanybooksontheshelf.Yourwatchisbroken.Youhadbetterbuyanewone.Youhadbetternotbelateforschool.DIYadviceSuzyisgivingDIYadvicetoherclassmates.Readtheadvicebelow.HelpSuzymakesentenceswithshould(not)orhadbetter(not).abeginyourworkwithoutreadingthembjoinaDIYclubtolearnmoreaboutitcbepatientdbuysometolearnmoreaboutiteplaywiththemwhenyoudoDIYjobs1.TherearemanyusefulbooksaboutDIY.Youshould/hadbetterbuysometolearnmoreaboutit.2.DIYisnoteasy.Youshould/hadbetterjoinaDIYclubtolearnmoreaboutit.Youshouldnt/hadbetternotbeginyourworkwithoutreadingthem.3.Instructionsareimportant.Youshould/hadbetterbecarefulwhenyouusethem.4.Scissorscanbedangerous.Youshould/hadbetterbepatient.5.SometimesitlltaketimetodoaDIYjob.HowtobeagoodstudentYou_belateforschool.You_listencarefullyinclass.should(not);hadbetter(not)shouldnt/hadbetternotshould/hadbetterDiscuss and fill in the blanks.You_lookoutofthewindowinclass.You_keepyourclassroomclean.You_befriendlytoothers.should/hadbettershouldntshould/hadbetterI.单项选择。1.TheTVistooloud.Please_.A.turnitdownB.toturnitdownC.turndownitD.toturndownit2._lateagain,Bill!A.DonttobeB.DontbeC.NotbeD.Benot3._crosstheroaduntilthetrafficlightsturngreen.A.NotB.WontC.DoesntD.Dont4._methetruth,orIllbeangry.A.TellingB.TotellC.ToldD.TellII.句型转换。1.Willyoupleasereaditagainmoreslowly?(改为祈使句)_againmoreslowly,please.2.Ifyoudontlistentome,Illgo.(改为同义句)_me,orIllgo.3.Theteachersoftentellthestudentsnottobecareless.(改为祈使句)_careless,please.4.PleasesitnexttoNancy.(改为否定句)_nexttoNancy.ReaditListentoDontbeDontsitIII.完成句子。1.你应该在南京换火车。_changetrainsatNanjing.2.你最好在下雨前回家。_beforetherainstarts.3.现在你最好别打棒球了。_baseballnow.4.不要把金鱼放在阳光下。_thegoldfishinthesun.YoushouldYoudbettergohomeYouhadbetternotplayDontput1.Trytogiveinstructions.2.Trytouseshould(not)andhadbetter(not)togiveadvice.