It will make your parents happy if you get good grades in the exam.

问题描述:

It will make your parents happy if you get good grades in the exam.
和if引到从句的关系

It (形式主语)will make(谓语) your parents(宾语) happy (宾补)if you get good grades in the exam(条件状语从句)真正主语是谁?这里主语就是It , 它可不是形式主语,它指代Your getting good grades in the exam. 这回事如果把it 看成修饰主语,此句可没有真正主语哟, if 是不可能引导主语从句的