Over, above or on top of?
Over (covering something)
"Keep the towel over your shoulders.
Above( at a higher level)
"The plane flew above the clouds.
We can use either over and above to mean` vertically at a higher level`:
"A helicopter was above/over the ship.
If we refer to two birds on a tree, we say that one bird is above the other bird ( we are concerned with a higher level , but not vertical). We cannot use over.
We use both over and above to refer to rank:
"A general is over/above a lieutenant.
On top of ( touching):
"Put the dictionary on top of the shelf.
Under ( covered by), underneath (completely covered by)
"Put a mat under/underneath the coffee pot.
Below is the opposite of above. It refers to position.
"The water was just below my knees.