If it were to snow tomorrow, they wouldn't go out.

If I were to do it, I would do it in a different way.

If he got there this afternoon, he would buy a map of the city.

If I should be asked/were asked /were to be asked to go, I'd certainly go.

特别注意：

1. 如非真实条件句的谓语含有系动词were或助动词had或should等词，可将if省 略，而把were，had或should 放在主语之前，变为虚拟倒装句，这和带有if的虚拟条件从句所表示的含义完全相同。

If I were you, I would get up early every morning. →

Were I you, I would get up early every morning.

Had you arrived at the station ten minutes earlier yesterday, you could have caught the train.

Should there be a flood, what should we do?

Were they here now, they could help us.

2. if 虚拟句的省略。

Given enough money, we could have done it much better.

3.有时用介词短语代替虚拟语气的条件句。

Fish can't live without water. 没有水，鱼就不能活。

4.if only 要是，只要，但愿

If only we could see each other once! 但愿我们能相见一次!

If only I had listened to his advice! 我要是听了他的劝告就好了！

5.虚拟语气的混合条件句：即条件从句和主句时态不一致。

"If I had missed" said William Tell, "and had shot too low, I was going to use this arrow on you."

If you had listened to the teacher carefully yesterday, you could answer the question now.

2) 虚拟语气在主从复合句中的用法:

I. 虚拟语气在宾语从句中的用法

1. wish+that 从句，表示的是一种虚拟语气，宾语从句中的动词所表示的动作表示的只是一种不能实现的愿望、要求。其中谓语动词的形式和对应用法如下表所述：

用 法 形 式 例 句

表示对现在情况的虚拟

wish+从句主语+动词过去式或were I wish I knew something about programming.

I wish I were as strong as you.

表示对现在进行情况的虚拟 wish+从句主语+ were doing I wish I were sleeping.

I wish it weren't raining.