he is senior now and I have no way to further

push him :(. He said he knows all grammer, which i know he is wrong. I, maybe like most chinese parents, when seeing his mistakes, always try to point out and help him. I agree with you that most ABC are doing better in grammer than other kids. Indeed even he missed one grammer question on act, he still got 36 on that section. 

I think he will learn his lesson from college.