Prepositions of place "in, on, at"

Prepositions of place A preposition is used to to say where the people, animals or things are.

at	in	on
When we are tinking about a particular point or position. e.g. The postman is at the door.	In  expressions: In the,  middle, in the sea, in the sky, in bed, in hospital, in prisión, in a newspaper, in a magazine, in a book, in a picture, in a shot, in a photo, in the world, in the lesson, in the country	In the expressions: On the left / on the right, on a platform, on a page, on the screen, on the beach, on the coast, on a map, on a farm, on a menú, on the first floor/on the second floor,  on a chair (except in an armchair)
To say where an event take place. e.g. There are a lot of  poeple at the concert / at the theatre / at the party.	With the names of towns, cities, countries and continents. e.g. in Milan, in Bogotá, In Egypt, in South America	We use on/at the corner of a street but we use in the  corner of a room.
With addresses when we mention the house number. e.g. I live at 16th street	We use "in" when we are thinking about the building itself. e.g. It was hot in the cinema (inside the building). However we use at when we are thinking about the normal function of the building e.g. My parents are at the cinema (they are watching a film).
To talk about  a person’s house or business. e.g. at Jose’s house, at the doctor’s

Note: -          When we talk about a means of transport, we use the preposition by e.g.by car/ by bus/ by train / by taxi / by plane / by boat but we use on foot and is not posible to use the preposition by when there is an article (a, an, the) or a possissive adjective (my, your, his, etc) or the possessive case before the means of transport. e.g. on the train, not by the train, in your car, not by your car, in Claudia’s car not by Claudia’s car. This article was published by  Prof. Carlos Olarte Virtual English Tutor CIMM - Sogamoso