帮我看看这个英文句子.

这句话的意思是当你到的时候,我已经剪完头发了。
注意前面“你到的时候”是已经发生了所以是过去时,又因为剪头发在你到的时间前面,
所以是过去的过去即过去完成时。过去完成时的形式是had+动词的过去分词
时态有16种、一般现在时 I have my hair cut。
一般过去时 I had my hair cut。
一般将来时 I will have my hair cut。
一般过去将来时 I would have my hair cut。
现在进行时 I am having my hair cut。
过去进行时 I was having my hair cut。
将来进行时 I will be having my hair cut。
过去将来进行时 I would be having my hair cut。
现在完成时 I have had my hair cut。
过去完成时 I had had my hair cut。
将来完成时 I will have had my hair cut。
过去将来完成时I would have had my hair cut。
现在完成进行时I have been having my hair cut。
过去完成进行时I had been having my hair cut。
将来完成进行时I will have been having my hair cut。
过去将来完成进行时I would have been having my hair cut。
如果有错误 请指正 我打的有点眼花 其中有6种貌似高中不要求掌握。。