Unit4whenwasitinvented?语法：被动语态.主动语态与被动语态：英语动词有两种语态,即主动语态(TheActiveVoice)与被动语态（ThePassiveVoice)。主动语态表示主语是动作的执行者;被动语态表示主语是动作的承受者。e.g.1.TheymaketrainsinZhuzhou.2.Thefarmersgrowcottoneveryyear.主动语态被动语态主动语态被动语态TrainsaremadeinZhuzhou.Cottonisgrownbythefarmerseveryyear.Thepassivevoice被动语态被动语态主动语态表示主语是动作的执行者被动语态表示主语是动作的承受者（在被动语态中动作的执行者有时用by短语表示出来.）被动语态的构成构成:(助动词)be+done(及物动词的过去分词)be随着时态的变化而变化Thepassivevoice.被动语态被动语态主动语态改被动语态主动语态改被动语态::Bellinventedthetelephonein1876.wasby各种时态被动语态的公式时态一般现在时一般过去式现在进行时过去进行时一般将来时过去将来时现在完成时过去完成时情态动词am/is/are+donewas/were+doneam/is/are+being+donewas/were+being+donewillbedonewouldbedonehave\hasbeendonehadbeendoneV情态+bedone主+do/does主+did主+am/is/are+doing主+was/were+doing主+willdo主+woulddo主+have\hasdone主+haddone主+V情态+do主动语态被动语态e.gManypeoplespeakEnglish.Englishisspokenbymanypeople.主动语态变被动语态的步骤：1、到主动句中的第一个实义动词后面找到动作的承受者，变为被动语态的主语（变为主格）；2、将谓语动词变为被动结构，套公式；3、由by加上主动句的主语（变成宾格），当不强调动作的执行者时，常省略。4.其它成分不变。Thepassivevoice被动语态被动语态主动语态变被动语态的结构图主动语态变被动语态的结构图::Bellinventedthetelephonein1876.ThetelephonewasinventedbyBellin1876.主语谓语动词过去时宾语时间状语主语谓语动词的过去分词宾语时间状语Exercises（将下列句子变为被动语态）1.Wehaverunoutofallthefood.2.Weshouldallowteenagerstomaketheirowndecisions.3.Theyarebuildingthehouse.4.Wewillfillthecupwithsomewater.5.Whoinventedthetelephone?Allthefoodhasbeenrunoutof(byus).Teenagersshouldbeallowedtomaketheirowndecisions(byus).Thebuildingisbeingbuilt(bythem).Thecupwillbefilledwithsomewater(byus).Whowasthetelephoneinventedby?Bywhomwasthetelephoneinvented?注意问题一、英语中的可以带双宾的动词，变被动语态有两种变法:若人（间宾）作主语，后面直接抄上物；若物（直宾）作主语，后面的人之前必须加介词to或者for.如：Igavehimagiftyesterday.(人作主语）(物作主语）Heagiftwasgivenbymeyesterday.Igavehimagiftyesterday.Agiftwasgiventohimbymeyesterday.如：Myparenthaveboughtmeabike.(被动）人作主语：物作主语：Ihavebeenboughtabikebymyparents.Abikehasbeenboughtformebymyparents.二、使役动词（make,let,have）;以及感官动词（see,hear,find,notice,watch等），后面接sb.dosth时，变被动语态时，do要变成todo.如：Thebossmadethemworkforalongtime.(被动）Theyweremadetoworkbytheboss.foralongtime再如：Weoftenseehimplayinthepark.(被动）Heisoftenseentoplayinthepark(byus).即：makesb.dosth.变被动sb.bemadetodosth.seesb.dosth.变被动sb.beseentodosth.三、不定式todo的被动结构是tobedone现在分词/动名词doing的被动结构是beingdone如：Youarelucky__________________bythereporter.(interview)Tomwenttothepartywithout____________.(invite)tobeinterviewedbeinginvited四、如何判断句子为被动语态：1.句子中有bysb.2.句子的主语为物时，大部分的句子为被动语态3.动词或介词后面应该带的宾语，没有出现。如：We________nottospeakinclass.(tell)Nobodylikes_____________at.(laugh)Iremember__________________bytheteacher.(encourage)beinglaughedaretold\tobelaughedbeingencouraged五、被动语态变主动语态步骤：1.找到bysb.，将sb.变为主格放在主语的位置，by去掉。（若句中没有bysb.，根据句子的意思自己加主语we/they.）2....
