现在be /do 过去were/was /did 将来be doing /will do 过去将来would/should do 现在完成has/have done 过去完成had done 将来完成will have done 过去将来完成should have done 现在进行be doing 过去进行were/was doing 将来进行will/shall be doing 过去将来进行would/should be doing 现在完成进行have been doing 过去完成进行had been doing 将来完成进行will/shall have been doing 过去将来完成进行would /should have been doing