把主动语态改为被动语态,可以遵循以下几个步骤：

　　1.把宾语变成被动语态中的主语；

　　2.找出谓语动词,变成相应的被动.如：一般式变成bedone.过去式变成was/weredone；

　　3.把主语变成介词by的宾语；

　　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.