英语中的虚拟语气是怎么一回事？

虚拟语态指不可能发生的事，你当作假设来讲。现在多称为第三条件句。

比如：
1)非虚拟语态（真实条件句）：
If it rains tomorrow, I won't go there.
(如果明天下雨，我就不去了。--可能下雨)

2）虚拟语态（费真实条件句）
If it rained today, it would be cooler.
(如果今天下雨，就会凉快些。--此时此刻并没有下雨)

其他：

If I were you, I would do it this way. (我不可能是你)

If I were the president of the U.S., I would do...(你不可能是美国总统)

虚拟语气是一种动词形式，表示说话人的一种愿望，假设，怀疑，猜测，建议等含义，虚拟语气所表示的含义不是客观存在的事实。 If I were you, I'd take them away. 如果我是你的话，我就会带走他们。 If I had met Li Hua, I could had told him. 如果我碰见了李华，我就告诉他了。 If I had time. I could come to help you. 如果我有时间，我会来帮助你的。 He suggested that our class should be divided into five groups. 他建议说我们的班应该分成五个小组。 He speaks to us as if he had been there. 他给我们讲的好象他去过那儿。
虚拟语气的用法

1) 虚拟语气用在简单句中，表示祝愿，命令。
May you be happy. 祝你幸福。
May you have a good time. 祝愿你玩的痛快。
May the friendship between us last long. 祝愿我们的友情天长地久。
Have a good journey