一、 被動語態(tài)的用法：1.一般現(xiàn)在時的被動語態(tài)構(gòu)成：is / am / are + 及物動詞的過去分詞 Our classroom is cleaned everyday.I am asked to study hard.Knives are used for cutting things.2.一般過去時的被動語態(tài)構(gòu)成：was / were + 及物動詞的過去分詞 A new shop was built last year.Dinosaur eggs were laid long long ago.3.現(xiàn)在完成時的被動語態(tài)構(gòu)成：has / have + been + 及物動詞的過去分詞 This book has been translated into many languages.Many man-made satellites have been sent up into space by many countries.4.一般將來時的被動語態(tài)構(gòu)成：will+ be + 及物動詞的過去分詞 A new hospital will be built in our city.Many more trees will be planted next year.5.含有情態(tài)動詞的被動語態(tài)構(gòu)成：情態(tài)動詞+ be + 及物動詞的過去分詞 Young trees must be watered often.Your mistakes should be corrected right now.The door may be locked inside.Your homework can be handed in tomorrow.6.現(xiàn)在進(jìn)行時的被動語態(tài)構(gòu)成：am / is / are + being + 及物動詞的過去分詞 Uncle Wang is mending my bike now.→ My bike is being repaired by Tom now.They are planting trees over there.→ Trees are being planted over there by them.7.不定式的被動語態(tài)：to + be + 及物動詞的過去分詞 There are two books to be read.→ There are twenty more trees to be planted.二、 怎樣把主動語態(tài)改成被動語態(tài)?例：1.Bruce writes a letter every week.→A letter is written by Bruce every week.2.Li Lei mended the broken bike this morning.→The broken bike was mended by Li Lei this morning.3.He has written two novels so far.→Two novels have been written by him so far.4.They will plant ten trees tomorrow.→Ten trees will be planted by them tomorrow.5.Lucy is writing a letter now.→A letter is being written by Lucy now.6.You must lock the door when you leave.→the door must be locked when you leave.