when you are learning a new preposition , read many examples about it
for example the preposition " in "
1- at a point within an area or a space:
a country in Africa
The kids were playing in the street.
It’s in that drawer.
I read about it in the paper.
2- within the shape of sth; surrounded by sth:
She was lying in bed.
sitting in an armchair
Leave the key in the lock.
Soak it in cold water.