被动语态的句子是以《be动词+过去分词》的形式来表达,如果要特别强调动作或行为的执行者时,句子后面需接by～,译为“被（由）……”.1被动语态的句型肯定句：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～）?被动语态的时态是由be的时态决定的,be是什么时态,全句就是什么时态,be动词后面的过去分词不变.一、被动语态的用法：1.一般现在时的被动语态构成：is/am/are+及物动词的过去分词Ourclassroomiscleanedeveryday.Iamaskedtostudyhard.Knivesareusedforcuttingthings.2.一般过去时的被动语态构成：was/were+及物动词的过去分词Anewshopwasbuiltlastyear.Dinosaureggswerelaidlonglongago.3.一般将来时的被动语态构成：will+be+及物动词的过去分词Anewhospitalwillbebuiltinourcity.Manymoretreeswillbeplantednextyear.4.现在进行时的被动语态构成：am/is/are+being+及物动词的过去分词UncleWangismendingmybikenow.→MybikeisbeingrepairedbyTomnow.Theyareplantingtreesoverthere.→Treesarebeingplantedovertherebythem.5.现在完成时的被动语态构成：has/have+been+及物动词的过去分词Thisbookhasbeentranslatedintomanylanguages.Manyman-madesatelliteshavebeensentupintospacebymanycountries.6.过去进行时的被动语态构成：was/were+being+及物动词的过去分词Theboywasbeingoperatedonwhenhisparentshurriedtothehospital.Thenewroadwasbeingmade.*过去将来时：should/would+havebeen+及物动词的过去分词*过去将来完成时:should/would+havebeen+及物动词的过去分词7.过去完成时的被动语态构成：had+been+及物动词的过去分词Theclassroomhadn’tbeencleanedbeforetheteachercame.TheticketshadbeensoldoutberoreIcametothecinema.8.将来完成时的被动语态构成：shall/will+havedoneTheywillhavebeenmarriedfor20yearsbythen.TheprojectwillhavebeencompletedbeforeMay.9.含有情态动词的被动语态构成：情态动词+be+及物动词的过去分词Youngtreesmustbewateredoften.Yourmistakesshouldbecorrectedrightnow.Thedoormaybelockedinside.Yourhomeworkcanbehandedintomorrow.二、怎样把主动语态改成被动语态?把主动语态改为被动语态非常简单,可以遵循以下几个步骤：1.先找出谓语动词；2.再找出谓语动词后的宾语；3.把宾语用作被动语态中的主语；4.注意人称、时态和数的变化.例：1.Brucewritesalettereveryweek.→AletteriswrittenbyBruceeveryweek.2.LiLeimendedthebrokenbikethismorning.→ThebrokenbikewasmendedbyLiLeithismorning.3.Hehaswrittentwonovelssofar.→Twonovelshavebeenwrittenbyhimsofar.4.Theywillplanttentreestomorrow.→Tentreeswillbeplantedbythemtomorrow.5.Lucyiswritingaletternow.→AletterisbeingwrittenbyLucynow.6.Youmustlockthedoorwhenyouleave.→thedoormustbelockedwhenyouleave.三、使用被动语态应注意的几个问题：1.不及物动词无被动语态.Whatwillhappenin100years.Thedinosaursdisappearedabout65millionyearsago.2.有些动词用主动形式表示被动意义.Thispenwriteswell.Thisnewbooksellswell.3.感官动词或使役动词使用省略to的动词不定式,主动语态中不带to,但变为被动语态时,须加上to.例：makesomebodydosomething→somebody+be+madetodosomethingseesomebodydosomething→somebody+be+seentodosomethingAgirlsawmywalletdropwhenshepassedby.→Mywalletwasseentodropbyagirlwhenshepassedby.Thebossmadethelittleboydoheavywork.→Thelittleboywasmadetodoheavyworkbytheboss.4.如果是接双宾语的动词改为被动语态时,直接宾语(物)作主语,那么动词后要用介词,这个介词是由与其搭配的动词决定.Hegavemeabook.→Abookwasgiventomebyhim.Heshowedmeaticket.→Aticketwasshowntomebyhim.Myfatherboughtmeanewbike.→Anewbikewasboughtformebymyfather.5.一些动词短语用于被动语态时,动词短语应当看作一个整体,而不能丢掉其中的介词或副词.Wecan’tlaughathim.→Hecan’tbelaughatbyus.Helistenstotheradioeveryday.→Theradioislistenedtobyhimeveryday.Thenurseistakingcareofthesickman.→Thesickmanisbeingtakencareofbythenurse.