if或unless引导的条件状语从句应该用什么时态啊

问题描述:

if或unless引导的条件状语从句应该用什么时态啊

例子:1.If he goes ,i will.
2..If I were you ,I wouldn' have lost the chance.
1 ,2句中if用法也不一样,分别为真实条件句和虚拟条件句。unless=if 。。。。not 用于真实条件句,不用于虚拟条件句

一般现在时态