虛擬條件句的從句部分含有were， should， 或had時， 可省略if，再把were， should或had 移到從句的句首，實行倒裝。例如：

Were they here now， they could help us. =If they were here now， they could help us.他們現在在的話，就會幫助我們了。

Had you come earlier， you would have met him. =If you had come earlier， you would have met him.你來得早一點，就碰到他了。

Should it rain， the crops would be saved. =Were it to rain， the crops would be saved.假如下雨，莊稼就有救了。

注意：在虛擬語氣的從句中，動詞’be’的過去時態一律用"were"，不用was，即在從句中be用were代替。例如：

If I were you， I would go to look for him. 如果我是你，就會去找他。

If he were here， everything would be all right. 如果他在這兒，一切都會好的。

典型例題

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

A. If were I B. I wereC. Were ID. Was I

答案C. 在虛擬條件狀語中如果有were， should， had這三個詞，通常將if省略，主語提前， 變成 were， should， had +主語的形式。但要注意，在虛擬條件狀語從句中，省略連詞的倒裝形式的句首不能用動詞的縮略形式。如我們可說 Were I not to do， 而不能說 Weren’t I to do.