Preposition Across : from one side to the opposite
(a). के उस पार,
on the opposite side of.
Her house is across the river .
(b). एक छोर से दूसरे छोर तक,
from on side to the other side of.
something Can you swim across the river.
There is a bridge across the river.
Preposition Above : In a higher position
(a). के ऊपर (लेकिन सटा हुआ नहीं ),
A sword was hanging above his head.
The plane is flying above the clouds.
(b). से परे /से ऊपर,
beyond the reach of,more than.
He is above suspicion.
We should value honour above life.
The applicants should be above the age of twenty.