We will go fishing if doesn't rain tomorrow.为什么用doesn't rain 而不用won't rain呢

问题描述:

We will go fishing if doesn't rain tomorrow.
为什么用doesn't rain 而不用won't rain呢

We will go fishing if doesn't rain tomorrow
这是if引导的条件状语从句,主将从现
主句是【We will go fishing 】
加在if后面的是从句,所以用一般现在时,这是固定用法