虛擬條件句的從句部分如果含有were, should, 或had, 可將if省略，再把were, should或had 移到從句句首，實(shí)行倒裝。
　 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：
　 在虛擬語(yǔ)氣的從句中，動(dòng)詞'be'的過(guò)去時(shí)態(tài)一律用"were"，不用was， 即在從句中be用were代替。
　 if i were you, i would go to look for him.
　　 如果我是你，就會(huì)去找他。
　 if he were here, everything would be all right.
　　 如果他在這兒，一切都會(huì)好的。

典型例題
　_____ 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. 在虛擬條件狀語(yǔ)中如果有were, should, had這三個(gè)詞，通常將if省略，主語(yǔ)提前, 變成 were, should, had +主語(yǔ)的形式。但要注意，在虛擬條件狀語(yǔ)從句中，省略連詞的倒裝形式的句首不能用動(dòng)詞的縮略形式。如我們可說(shuō) were i not to do., 而不能說(shuō) weren't i to do.