教学课件外研版八年级上册英语（25秋新教材）Unit5Playbytherules?GrammarLearningObjectivesInthislesson,youwill:1.mastertheusageofinfinitivesasadverbialsofpurpose.2.completeexercisesonusinginfinitivestoexpresspurpose.3.shareastoryoffollowingrulesusingtargetlanguages.(a)Igotonthetraintogohome.(b)Iwenttoaquietareainordertoread.(c)IcoveredmynosesoastoreducethesmellcomingfromMrSmellyFood.Readthesentencesfromthereadingpassageandsummarisethegrammarrules.Whatdoestheinfinitiveshow?Isitthepurpose,reason,orresultoftheaction?Theseinfinitivesallshowthepurpose!Nowfindmoresentenceswiththesestructuresinthereadingpassage.Iturnedaroundsoastoseetheotherpassengers’?faces.IcoveredmyearsinordertoblockthenoisecomingfromRockGirl.GrammarRules动词不定式可以在句中作目的状语，表示行为动作的目的。e.g.TheWWFisworkinghardtosavealltheanimals.世界自然基金会正在努力挽救所有的动物。Shepractiseseverydaytoimprovehersingingskills.她每天都在练习，以提高自己的歌唱技巧。e.g.Dylantrainedhardtoimprovehisbasketballskills.Dylan刻苦训练以提高自己的篮球技术。=Toimprovehisbasketballskills,Dylantrainedhard.在作目的状语时，不定式既可以放在句首，也可以放在句尾。放在句首时通常加逗号。除了直接使用todosth之外，我们还可以使用inordertodosth和soastodo?sth来表示行为动作的目的。e.g.Hessavingmoneyinordertobuyanewcomputer.为了买一台新电脑，他正在攒钱。Lindastartedworkearlysoastofinishitbyfive.Linda很早就开始工作，以便在五点前完成。inordertodosth更正式，强调目的，可位于句首或句中。否定结构：inordernottodosth.e.g.Theyleftearly?inordertocatch?thefirsttrain.他们早早离开，为了赶上首班火车。Inordertosucceed,youmustworkhard.为了成功，你必须努力。Sheturneddownthemusicinordernottodisturbneighbors.她调低音乐，以免打扰邻居。soastodosth较正式，一般不位于句首。否定结构：soasnottodosth.多用于避免负面情况。e.g.Shespokequietly?soasnottowake?thebaby.她轻声说话，以免吵醒宝宝。Hecheckedthemap?soastoavoid?gettinglost.他查看地图，以防