真实条件句，
语法学术语，用于陈述语气，假设的情况可能发生，其中 if 是如果的意思。
如：We shall go out when you finish your holiday homework.
如：I would not go with you if it rained the next day.
如：Wake me up if I am still sleeping at 7.
(4)当
主句为一般将来时，由
as soon as,after,before,till/until,when,if等引出的
状语从句常用现在完
如：I will help you as soon as I have finished my homework.
If he comes, he will bring his violin.
The volleyball match will be
put off if it ___.
A. will rain B. rains C. rained D. is rained
(错) If you leave now, you are never going to regret it.
(对) If you leave now, you will never regret it.