虚拟条件句的从句部分如果含有were, should, 或had, 可将if省略，再把were, should或had 移到从句句首，实行倒装。

例句：

Were they here now, they could help us.

=If they were here now, they could help us.

Had you come earlier, you would have met him

=If you had come earlier, you would have met him.

Should it rain, the crops would be saved.

=Were it to rain, the crops would be saved.

注意：

在虚拟语气的从句中，动词be的过去时态一律用were，不用was， 即在从句中be用were代替。

例句：

If I were you, I would go to look for him.

如果我是你，就会去找他。

If he were here, everything would be all right.

如果他在这儿，一切都会好的。

例题：

_______ to do the work, I should do it some other day.

A. If were I；B. I were；C. Were I；D. Was I；

答案：C。

解析：在虚拟条件状语中如果有were, should, had这三个词，通常将if省略，主语提前, 变成 were, should, had +主语的形式。但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说 Were I not to do.，而不能说 Weren't I to do。