我们都知道，在大学英语四级考试中，单独考察英语四级语法的题型很少，但是英语四级语法知识点却贯穿整张试卷，下面是新东方网英语四级频道为大家整理的大学英语四级语法知识，希望可以为大家带来帮助。

2017年12月大学英语四级语法大全目录英语四级听力训练

16.4 虚拟条件句的倒装

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。

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。

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。

典型例题

_____ 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.

2017年12月大学英语四级语法大全目录