Sometimes modal verb and conditional sentence is tricky for non-native speaker like me.
I, you and he met yesterday. He said nothing. I and you (except him) are meeting today again. I don't know if he knew about it or if he didn't know about it, when we met yeseterday. In this situation,
a. If he knew it, he would tell us.
b. If he knew it, he would have told us.
c. If he had known it, he would have told us.
Which is correct? I think a or b, not c.
Sorry for my poor English sentences, but I hope you understand my question. ^^