虚拟预期在条件句中的应用：

1： If i were you , i would make better use of time at school.

如果我是你，我会更好地利用在学校的时间。

2：If you had taken your teacher’s advice ,you wouldn’t have failed in the exam .

如果你早听老师的话，考试就不会不及格。

3：If it should rain ,we would change our plan.

万一下雨的话，我们就改变计划。

用法

条件从句的谓语动词 主句的谓语动词

与现在事实相反 动词过去式 SHOULD+动词原形

WOULD+动词原形

与过去事实相反 HAD+过去分词 SHOULD HAVE +过去分词

WOULD HAVE +过去分词

与将来事实可能 动词过去式 SHOULD+动词原形

相反 SHOULD+动词原形 WOULD+动词原形

WERE TO+动词原形

注、：1在主句中SHOULD 用于第一人称，WOULD 用于任何人称。

2主句中可用COULD，MIGHT代替SHOULD WOULD。

3条件从句中一律用WERE，在口语或非正式语句中用WAS。但“IF I WERE YOU…… ”是固定说法