Грамматически верно ли построены эти предложения на английском?

1. I'd have gone to university a year earlier if i'd passed my exams.
2. You would have passed your exams if you'd worked a bit harder.
3. "What would you have studied if you hadn't studied history?" "I don't know. I 'd have studied politics."
4. If I had known the course was going to be so dull, I'd have gone somewhere else/
5. If you don't recommend that university to me, I will try to get a place at Cambridge university.
6. If you had gone somewhere else, you woldn't have met your wife!