1.一般现在时:主语+do/does(现在分词)
e.g We clean the room every day.
2.一般过去时:主语+did
e.g We cleaned the room just now.
3.现在进行时:主语+am/is/are doing
e.g We are cleaning the room now.
4.过去进行时:was/were doing
e.g We were cheaning the room at 5:00 yesterday afternoon.
e.g 5.现在完成时:have/has done
We have cleaned the room already.
6.过去完成时:had done
e.g We had cleaned the room before he arrived.
7.一般将来时:will do/
e.g We will clean the room tomorrow.
8.过去将来时:was/were to /would do
e.g He said he would clean the room next.
二、八种时态所用的时间状语：
一般现在时 every …,sometimes,at …,on Sunday,
一般过去时 yesterday,last week,an hour ago,the other day,in 1982,just now
一般将来时 next…,tomorrow,in+时间,
现在完成时 for,since,so far,ever,never,just,yet,till/until,up to now,in past years,always,recently
过去完成时 before,by,until,when,after,once,as soon as
过去进行时 this morning,the whole morning,all day,yesterday,from nine to ten last evening… when,while
将来进行时 soon,tomorrow,this evening,on Sunday,by this time,tomorrow,in two days,tomorrow evening
三、时态一致的两种情况：
1) 如果从句所叙述的为真理或不变的事实,则永远用现在时.
At that time,people did not know that the earth moves.
He told me last week that he is eighteen.
2) 宾语从句中的助动词ought,need,must,dare 时态是不变的.
He thought that I need not tell you the truth.
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