牛津英语9A第五单元语法（2）学案学习目标：1.should和oughtto与must区别2.must与haveto3.hadbetter4.Whynot…?/Whydon’tyou…?1.should和oughtto与must区别用should/oughtto可以表示“劝说”或“督促”，和must一样，但三者语气强弱不同。用should语气比较肯定一些，说话人的主观信心要强烈一些。含有责任的意思。用oughtto则口气上不那么坚定。用must则在口气上最强烈，含有责任的意思。例如：Youmustdoyourhomework.Youshouldspeaktoyourparentspolitely..Ioughttowritetohimtoday.2.must与havetomust表示“必须”，侧重于说话人的主观意志。haveto表示“必须”，侧重于客观的需要，含有“不得不”的意味。3.hadbetter(常缩写为’dbetter)，是一固定词组，表示“最好”，用于表示对别人的劝告、建议或表示一种愿望。hadbetter后面加动词原形，即hadbetterdosth.不论主语是第几人称,句子无论是何种时态，hadbetter形式不变。hadbetter的否定形式为hadbetternotdosth表示“最好不要做……”。如：You’dbetternotmissthelastbus.You’dbetternotplayontheroad.It’sdangerous.You’dbetterputonthecoat.It’scoldoutside.4.Whynot…?/Whydon’tyou…?这两种句型结构常用于说话人向对方提出一个建议，意思是“不……？”；“为什么不……？”Whynot…?/Whydon’tyou…?后面必须跟动词原形。如：Whynotgoswimming?=Whydon’tyougoswimming?Whydon’tyougooutforawalk?=Whynotgooutforawalk?练习：一单项选择1.Mymotherwasill.I______stayathometolookafterher.A.mustB.havetoC.couldD.can2.---____goshoppingwithyourfather?---That’sagoodidea.A.Whydon’tB.WhynotC.DoD.Does3.You___giveupsmoking.A.wouldbetterB.hadbetterC.wouldbettertoD.hadbetterto4.Whydon’tyou_____climbingwithustomorrow?A.togoB.goingC.goD.goes5.Cars,busesandbikes___stopwhenthetrafficlightschangestored.A.canB.mayC.mustD.need6.It’stoohot.Perhapsyou______swimmingthisafternoon.A.mustgoB.shouldgoC.maygoD.cango7.Tomakeourhometownmorebeautiful,you__throwrubbishintotheriver.A.needn’tB.mustn’tC.mustD.need8.Howinterestingthenewsis!Why_____joinus?用心爱心专心1A.won’tB.noC.don’tD.not二、完成句子1.Youlooksotired.____________(你最好不要学习得太晚).2.We____________(我们应该每天保持教室整洁和干净).3.___________(或许我们可以向朱老师求助).Heiskindandhelpful.4.___________(你为什么不出去啊？)Youshouldnotstudyallthetime.5.___________(你得保持安静)whilereadinginthelibrary.三、分别用should,oughtto,hadbetter,haveto和must完成句子1.Washyourhandsbeforedinner.2.Makeawishwhenyoublowoutthecandlesonabirthdaycake.3.Drinkcoldwatertakendirectlyfromthefridge.4.Keepthetableclean.5.Eatvegetablesevenifyoudonotlikethem.四、用whynot和,whydon’tyou分别完成下列各句。1.Goshoppingwithme.2.AskyourfamilytoturnofftheTVwhileyouarestudying.3.Shareyourproblemwithyourparents.4.Writetomeifyouarestressed.用心爱心专心2
