Basic Grammar: Prepositions
ON
1. We use on with small islands:
Example: She spent her holiday on a small island.
2. We say that a place is on the coast / on a river / on a road:
London is on the river Thames.
Portsmouth is on the south coast of England.
IN
1. We say in when we talk about a building itself.
Example: She was in the church yesterday.
2. We usually say in with towns and villages:
Example: His parents live in New York.
Note the following expressions:
AT
at home
at work
at school 
at university
at college
at the station
at an airport
at the seaside
at sea
at reception
at the corner of a street
at the back of a building
at the front of a building
arrive at (with other places and events)
IN
in the newspaper
in bed
in hospital
in prison
in the street
in the sky
in an armchair
in a photograph
in a picture
in a mirror
in the corner of a room
in the back of a car
arrive in a country or town
ON
on a farm
on the left
on the right
on the ground floor
on the way
on the chair
on the radio
on television
on a horse
on the corner of a street
on the back of a letter
on the front of a letter
on the back of a piece of paper
TO - INTO - BY
We say "go / come / travel / fly / walk / return/ drive / have been etc. to a place or event:
We say "go into / come into = enter a room / building etc.:
Example:
Last year we flew to London.
We went to work at seven.
He opened the door and went into the room.
BY
We say by to say how we travel:
We went to Paris by plane.
I usually go to work by bike / by car / by underground / by bus.
BUT:
S