Above and over are both used to talk about position and height.
If something is higher than something else, but an imaginary line joining them is not vertical, you have to use above.
1. The trees rose above the houses.
If you go over something, you cross it and get to the other side.
2. Castle stepped over the dog.
3. …a soaring seagull swooping over Central Park.
If you are wearing two items of clothing one on top of the other, you can say that you are wearing one over the other.
4. Rudolph was wearing a sweater over a wool shirt, and a silk scarf.
You can use either above or over if something is higher than something else and an imaginary line could be drawn vertically joining them.
5. He opened a cupboard above the sink.
6. She leaned forward until her face was directly over the basin.
Above and over are also both used to talk about measurements.
7. You use over to say that a distance or period of time is longer than the one mentioned.
8. The plane flew at a height of over twelve thousand feet.
9. So we had this beautiful relationship for over a year.
You can use above or over when you are talking about a point that is higher than another point, especially a point on a scale.
10. The amount of tax you should pay is determined by what you earn above a certain figure.
11. Any money earned over that level is taxed at the rate of 59 per cent.
12. In each case I want to know the height of the man. Everybody above five feet eight inches is suspect.
Above and over are both used to talk about people’s ranks and importance relative to others.
You use above to talk about people who are more important and in a higher position than other people.
13. …behaving as if she was in a position above even the staff, and certainly above us.
If someone is over you, they give orders or instructions to you.
14. …an officer set in authority over him.