题目内容：

一个英语问题：I'll sweep the floor if you (would) clean the desks and chairs.
句子如题,我想知道为什么括号中要用would?if引导的从句的时态都要比主句的退后一步吗?

优质解答

这句话可以这样理如果是虚拟语气的话,就是一个错误的句子.
应该为：i'll sweep the floor if you clean the desks and chairs.
或者
i would sweep the floor if you would clean the desks and chairs.
看你是高中的题还是初中的题.