1. 当if后面接
一般现在时的动词时,表示对将来的一种推测. if sb do sth sb will/shall do sth. If you go with me, you shall be rewarded. 2. 当if后面接
一般过去时的动词时,则是一种
虚拟语气. if sb did sth sb would/should do sth. If I didn't make that mistake, I would't have suffered such a failure. 3. 当if后面接什么时态都可以时,if为“是否”的意思,句子为
宾语从句. sb do sth if sb do sth. He said if rain was stop. 由if引导的条件状语从句,时态应该是主将从现,就是说主句用
一般将来时,而从句用一般现在时表示将来。 例如 If it doesn't rain tomorrow, I will visit my former school. 这里从句就用一般现在时。 当然if引导的从句也可以用虚拟语气 例如If I got up early in the morning, I wouldn't miss the train.
追问你们这群人太不负责任了,随便一个复制粘贴就应付了,根本没看我的问题好吗?还科学芝麻团,真不配