▲你的老师总结的是对的，错综时间的虚拟语气主要就这两类。比如《薄冰高级英语语法》给出的例子就是针对这两种情况的：

If I had spoken to him yesterday, I should know what to do now. 假如昨天我对他说了，现在我就知道该怎么办了。

You would be much better now if you had taken my advice. 假如你接受了我的意见，你现在就会好得多。

If father hadn’t sent me, I shouldn’t be here. 假如父亲没有叫我来，我现在就不会在这里。

If he knew this, it would have had to be by accident. 假如他已知道此事，那一定是出于偶然的。

但《薄冰高级英语语法》补充了如下一条：

▲如条件从句用 if I were….，结果主句则可用表任何时间的虚拟形式，如：

If I were not busy, I would have come. 假如我不忙，我就会来了。(were 表过去)

If I were you, I would go. 假如我是你，我会去的。(were 表现在)