please remenber to say good bye to Mr.smith when you leave tomorrow

问题描述:

please remenber to say good bye to Mr.smith when you leave tomorrow
为什么leave不加will
i don't know when we will start charity show tomorrow
为什么什么start加了will

第一句是when连接的是时间状语从句,在时间状语从句中要用一般现在时代替将来时
第二句是when 连接的宾语从句,时间状语tomorrow在从句中要用将来时