The Difference between In and On

Shana Goodwin, August 26, 2021

In Spanish, the preposition “en” is used to indicate position in space or time. But in English, there are two prepositions that replace “en”: in and on. It can be difficult to know which one to use when, and although they are often interchangeable, here are a few general guidelines:

Talking about Space/Place

Use in to describe a position inside a limited space (in a house, in a box, in a book). Example: My aunt paints the ceramics in her house.

Also, use in when talking about cities, towns, states, or countries. Example: Her house is in Aregua.

Use on to describe a position above or supported by or in contact with something (on the desk, on the potter’s wheel, on the plate). Example: She puts the ceramics on the shelves when they are finished.

On is also used with street names. Example: My aunt’s house is on Las Residentas Avenue.

Talking about Time

Use in to describe a moment enclosed in a portion of time (parts of the day, months, years, seasons). Example: In September, my aunt sold twenty ceramic vases.

Use on when talking about specific dates. Examples: On Wednesday, she mixed up a new glaze. On Christmas Eve she receives the most orders.


When they are being used as prepositions of place, the opposites of in and on are “out” and “off.” Make sure not to confuse these either! For example, if your phone is in your pocket, it can fall out, but not off. If a cat is on a chair, it can jump off, but not out.

Useful Phrases with In

  • In addition (to) 
  • In advance         
  • In any case         
  • In case 
  • In control (of)    
  • In detail              
  • In fact  
  • In general           
  • In a hurry            
  • In no time          
  • In secret             
  • In the end          
  • In the meantime              
  • In person            

Useful Phrases with On

  • On average        
  • On behalf of      
  • On edge              
  • On foot
  • On good terms  
  • On one's own    
  • On your mind    
  • On purpose        
  • On second thought         
  • On target           
  • On time              

Photograph by Tetsuo Miyama