If I was on the inside, I could tell you what they were planning before they do

xingxihui

If I was on the inside, I could tell you what they were planning before they do it.
请问上面那句话的虚拟语气怎么理解呢？虚拟语气应该用什么时态呢？谢谢。

rollingstone

如果我知道内情,我就能在他们行动前获悉他们的计划.

haveit

我依稀记得高中时候学的虚拟语气是用If I were...的。