虚拟语气的三个基本句型分别是：

1. 与现在事实相反的假设：If I were you, I would do it.（如果我是你，我会做这件事。）

2. 与过去事实相反的假设：If I had done it, I would have succeeded.（如果我当时做了，我就会成功。）

3. 与将来事实相反的假设：If it should rain tomorrow, the picnic would be cancelled.（如果明天下雨，野餐将会取消。）