Above & Over

1) 'higher than': above or over

Above and over can both mean 'higher than'.

The water came up above/over our knees.
Can you see the helicopter above/over the palace?

2) 'not directly over': above

We prefer above when one thing is not directly over another:

We've got a little house above the lake.

3) 'covering': over

We prefer over when one thing covers and/or touches another:

There is cloud over the South of England.
He put on a coat over his pajamas.

We use over or across when one thing crosses another:

The plane was flying over/across Denmark.
Electricity cables stretch over/across the fields.

4) measurements: above

Above is used in measurements of temperature and height, and in other cases where we think of a vertical scale:

The temperature is three degrees above zero.
The summit of Everest is about 8000 metres above sea level.
She's well above average in intelligence.

5) ages, speeds, 'more than': over

We usually use over, not above, to talk about ages and speeds, and to mean 'more than':

You have to be over 18 to see this film.
The police said she was driving at over 110 mph.
There were over 100,000 people at the festival.

6) see above/over

In a book or a paper, see above means 'look at something written before'; see over means 'look on the next page'.