have是助词 v.aux.
1.
(加过去分词,构成完成时态)已经;曾经
They haven't finished the job yet.
他们尚未完成该项工作.
2.
(用于虚拟语气,表示与过去事实相反的假设)(假如那时)...的话
She might have come if she hadn't been so busy.
当时若不是那么忙,她是可能来的.