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)