我英语不好啊

1.
if引导的条件状语从句

I will visit my parent if I have time.

2.when引导的时间状语从句;

I am going to visit my parents when I have time.

3.because引导的原因状语从句等。

He will pass the exam because he studies hard all the time.

I will go swimming if it is sunny tomorrow.
这里其实用的也是将来时，只是if引导的从句用一般现在时替换一般将来时