主将从现是不是一定是主句一般将来时，从句用一般现在时？？？

这个用在条件状语从句当中
意思是：主句用一般将来时，从句从一般现在时
举例：I will stay at home,if it rains tomorrow
其中I will stay at home是主句 if it rains tomorrow 是从句

如果条件状语从句当中的时态不是一般现在时，那么一定是虚拟语气，可以用现在完成时，但不能用现在进行时

可以 比如：If you are going out,it's raining now.
还可都用一般时表必然习惯发生。If a baby is hungry,it cries.
If my dog hears any strange sounds,he barks.
If you eat bad plums,you get ill.
If I am happy,I smile.
If you have been walking all night,you need to have a rest.
If you are right,I am wrong.

还可都用一般时表必然习惯发生。If a baby is hungry,it cries.(=it will cry.)
主句还可以是祈使句或带情态动词的句子。如：You can't get there on time if you don't hurry up.
Call me when she comes.

主将从现一定是主句一般将来时，从句用一般现在时