虚拟语气中与现在相反可以省略if吗?如果可以该怎么倒装呢?

问题描述:

虚拟语气中与现在相反可以省略if吗?如果可以该怎么倒装呢?
比如说:If I attended the meeting,I would know that.可以把if省略,可以变成Did I attend the meeting,I would know that.

亲:只有were,had,should可以提前.