被动语态1.Teenagersshouldbeallowedtochoosetheirownclothes.语态：表示主语和谓语动词之间的关系。英语有两种语态，即主动语态和被动语态。助动词be有人称、数的变化,其变化规则与be作为连系动词时一样。如：Thedeskismadeofwood.Thedesksaremadeofwood.Heisaskedaquestionbytheteacher.bymanystudents.1.找宾语----即动作的承受者TheyplayfootballonSunday.Lucydoesthehomeworkintheevening.Theyoftenusecomputersinclass.WemakethesemachinesinBeijing.肯定句：主语＋be+过去分词＋(by~)否定句：主语＋benot＋过去分词＋(by~)一般疑问句：Be＋主语＋过去分词＋(by~)?特殊疑问句：疑问词＋be＋主语＋过去分词＋(by~)1.Theyboughttencomputerslastterm．Theybuiltthetallbuildinglastyear.Hetookgoodcareofhislittlebrotheryesterday.Wecleanedourclassroomjustnow.Theyusedthisroomforresting.3.一般将来时的被动语态结构：Wewillhaveasportsmeetingnextweek.Childrenwilltakesomephotosintheschoolyardtomorrow.Theheadmasterwillgiveatalkthisafternoon.4.含有情态动词的被动语态结构：1.Hecantakecareofthebaby.2.Lucymaydrawthepictures.3.Youmustturnoffthelights.4.TheyshouldlearnEnglishwell.5.现在进行时的被动语态的结构6.现在完成时的被动语态的结构表格：被动态基本结构Suchbooksarewrittenforchildren.这些书是为儿童写的。Ihaven’tbeentoldaboutit.没有人告诉我这件事如：1.Hegavemeabook.－Iwasgivenabookbyhim.（以I做主语）－AbookwasgiventomebyTom.（以物book作主语）2.HeteachesusEnglish.－WearetaughtEnglishbyhim.（以人当主语）－Englishistaughttousbyhim.（以物作主语）keep,make三类的动词常常有宾语补足语，在被动语态中，宾语补足语位置不变。Wekeepfoodfreshinthefridge.主谓宾宾补－Foodiskeptfreshinthefridge.Isawhimgointotheofficebuilding.－Hewasseentogointotheofficebuilding.不及物动词没有宾语，因此没有被动语态。但有的不及物动词后面加上介词及其他一些词类构成短语动词之后，其作用相当于及物动词，可以接宾语，因而也可以变为被动语态。在变成被动语态时，不能去掉构成短语动词的介词或副词.下列这些短语本身即是被动语态的形式，不需再加－bybecoveredwith…用…覆盖着beinterestedin…对…感兴趣besurprisedat…对…感到惊奇bemadeof（from）用…制造的即feel,hear,listen,have,make,let,look,watch,see,notice，这些词在主动句中，其后的动词不定式不加to，但变被动句时必须加to.（1）当主动结构中的宾语是反身代词和相互代词时，不能改为被动语态。Weoftenhelpeachother.我们常常互相帮助。（2）当谓语是表状态的及物动词时（如have,like,takeplace,belongto…）如：Iliketheseflowers.我喜欢这些花。Iwillhaveameeting.不说Ameetingwillbehad.应说Ameetingwillbeheld.把下列句子变成被动语态:Acarknockedhimdownyesterday.2）Twodoctorsandtennursesmakeupthemedicalteam．3）WhenIgotthere,theywerecuttingupafallentree．4)W