过去过去时就是过去完成时had done
将来过去时就是将来完成时will have done
还有过去将来过去时（过去将来完成时）would have done
将来将来时可能是will be going to
过去将来完成进行时是英语中最复杂的时态：
How long would you have been working on the project if you had not gone abroad?