I Wish I Had Studied Grammar at School

I wish I'd studied is not the same as I wish I study. We could say, I wish I had studied grammar at school. But the reality is I didn't. So when I was young, I didn't study grammar at school and now I regret it. That's my regret. If only if only I'd studied Spanish grammar - so then I contracted that past perfect had. You can actually contract have to apostrophe VE instead of I should have. Can you think of any examples, Reza? What about this? I should have studied harder."