If I did not have changed the way of studying , I would have got kicked out of school.-> If I hadn't changed my way of studying, I would have gotten kicked out of school. If I had tried it , I could have had a nice hair style now. -> Either if I had tried it, i could have had a nice hair style or if I had tried it I could have a nice hair style now. If you did not have studied hard , you would not have passed the exam. -> If you hadn't studied hard, you would not have passed the exam If he did have gone out , he would not have had this thing happened to him. -> If he hadn't gone out, he would not have had this thing happen to him Generally speaking : If both clauses are in the past, you need if + past perfect , could or would + present perfect -> If I HAD GONE to the movies yesterday, i WOULD HAVE SEEN my ex boyfriend. If you are talking about an unlikely situation but its the present or future, you need if + simple past , would / could + infinitive -> If I went to New York, I would see a Broadway show.

If I did not have changed the way of studying , I would have gotten kicked out of school.