条件句
虚拟条件句主要有下面两类:
表示现在及将来情况(表示纯然假设或实现的可能性不大的情况):
谓语主要形式如下(be多用were这个形式):
从句主句
过去式
would + 动词原形
if i were you, i wouldn’t lose heart.
how nice it would be if you could stay a bit longer.
表示过去情况的虚拟条件句(与事实完全相反的假设情况), 谓语主要形式如下:
从句
主句
had + 过去分词
would have + 过去分词
she would have come if we had invited her.
if i hadn’t taken your advice, i would have made a bad mistake,
you wouldn’t have caught cold if you had put on more clothes.
有时候, 条件从句表示的动作和主句表示的动作, 发生的时间是不一致的(如一个是过去发生的, 一个是现在发生的). 这时, 动词的形式要根据表示的时间来调整. 这种句子可以称为错综。