现在进行时: 主语+am/is/are doing
e.g We are cleaning the room now.
过去进行时: was/were doing
e.g We were cheaning the room at 5:00 yesterday afternoon.
现在完成时: have/has done
We have cleaned the room already.
过去完成时: had done
e.g We had cleaned the room before he arrived.
一般将来时: will do/
e.g We will clean the room tomorrow.
过去将来时: was/were to /would do
e.g He said he would clean the room next.