I find English is sometimes difficult if people speak it yoo quickly

问题描述:

I find English is sometimes difficult if people speak it yoo quickly
这里有带if的条件状语从句,为什么主句不用将来时而用一般现在时?

因为只有“主将从现”“主过从过”
没有“主现从现”
而且这句话是强调事实,所以主句从句都要用一般现在时