分词做定语过去：
1、The polluted water and air are harmful to people’s health.
2、A burnt boy is afraid of fire. 过去分词做标语： 1、He looked worried after reading the letter. 2、When we heard of it, we were deeply moved. 过去分词做状语： 1、Hit by the lack of fresh air,he got a bad headache. 2、Though feeling tired after the long journey,I still enjoyed meeting the aliens on the space station. 过去分词做宾补： 1、My grandfather had his old house rebuilt. 2、They kept the door locked for a long time.
Before:
1.BeforeIwenttobedlastnight,Ihadreadsomebooks.
2.BeforeIwatchedTV,Ihadfinishedmyhomework.
3.Beforethepolicegotthere,themurderhadrunaway.
4.BeforeIarrivedattheairport,hehadleft.
5.Beforeyouknewthetruth,Ihadknownthat. Bythetime: 1.Bythetimethattheteacherexplainedthisquestiontous,Ihadalreadyslovedit. 2.Bythetimeyouarrivedhere,hehadleft. 3.Bythetimetheywenttohome,thefirehadbeenputoff. 4.Bythetimeeveryoneknewthetruth,Ihadadmittedmymistaketomyteacher. 5.Bythetimewearrivedatthecinema,thefilmhadstarted. after: 1.Afteryouknewthat,ithadbeentoolate. 2.Aftertheyfoundthekeytothedoor,theownerofthehousehadbeenback. 3.AfterIrealizeditsimportance,ithadbeentoolate. 4.Afterwefinishedourwork,ithadbeen11o’clockinthenight. 5.Aftershetoldmetothrowawaythoseclothes,Ihadalreadywashedthem.