虚拟语气用于条件状语从句

虚拟语气表示说话人的愿望、假设、猜测或建议，而不表示客观存在的事实。虚拟语气通过谓语动词的特殊形式来表示。

下面分别介绍虚拟语气在各种句式中的用法。

（一）虚拟语气用于条件状语从句

虚拟条件句谓语动词的构成形式：

注意：（1）、主句中的 should 通常用于第一人称， would 可用于任何人称，同时也可根据意思用情态动词 could, might.

      （2）、“与将来事实相反”中的 B 式与 C 式之间的差别是“ were to + 动词原形”比“ should + 动词原形”所表示的

         实现的可能性更小。

      （3）、在与将来事实相反的句中，只有条件状语从句用 should 时主句才能用 B 式的祈使句。

1、表示与现在事实相反

If I were you , I should study English.

If he had time , he would attend the meeting.

2、表示与过去事实相反

If you had come yesterday , you would have met him.

3、表示与将来事实相反

If you came tomorrow , we would have the meeting.

If it were to\should rain tomorrow , the meeting would be put off.

If it should rain , don't expect me.(可接祈使句）

4、if 的省略

当从句中有 were ,had ,should ,would 等放在主语前可构成疑问句的词时，可省略 if ，用倒装形式。 例如：

Had she more money , she would dress fashionably.

Had you been here earlier , you would have seen him.

Should there be a meeting tomorrow , I would come.

Were I in school again , I would work harder.