On
* For surfaces:
* I placed the book on the table.
* The painting hangs on the wall.
* For days and dates:
* We're going to the beach on Saturday.
* The meeting is on March 15th.
* For transportation:
* I'm traveling on the train.
* She arrived on a flight from London.
* For specific locations within larger areas:
* The cafe is on Main Street.
* We live on the 5th floor.
In
* For enclosed spaces:
* I'm sitting in the car.
* The books are in the library.
* For general locations:
* She lives in London.
* We're going in the house now.
* For periods of time:
* I'll be done in a few minutes.
* We met in the summer.
* For materials:
* The chair is made in wood.
At
* For specific points or places:
* I'm at the bus stop.
* We met at the restaurant.
* For events and occasions:
* I'll see you at the party.
* The concert starts at 8 pm.
* For addresses:
* He lives at 123 Main Street.
* For general location without specific space:
* He's at work.
* She's at the beach.
Common Confusions and Tips
* In vs. On for cities: "In" is generally used for large cities, while "on" is used for smaller cities or towns. (e.g., "I live in London," but "The shop is on Oxford Street.")
* At vs. In for home: "At" is more general for home as a place, while "in" refers to being inside the house. (e.g., "I'm at home," but "He's in his room.")
* Prepositions can change the meaning: "The book is on the table" (it's resting on the surface) vs. "The book is in the table" (it's inside the table).
Practice makes perfect!
The more you read and write in English, the more natural these prepositions will become.