If I had known that,I could have helped you.had和known怎么都是过去式,have_英语解答

If I had known that,I could have helped you.had和known怎么都是过去式,have在这里是什么意思,为什么它不用过去式

人气：213 ℃　时间：2020-05-10 15:46:15

解答

这是虚拟语气,表示与事实相反的情况.
had known是过去完成时,have是助动词,是现在完成时的标志.
这一句表示与过去的事实相反.