Prepositions : In, On, and At

Preposition Usage :

•  “in” with periods of times and places. 
• “on” with specific days.
• “at” with specific times and specific places.

Notice how they are used in the following situations: 

preposition:

1. in :

• Time : Year, Month,In 1999, In December. 
• Place : Country, State, City, In Japan, In Utah, In Taipei.

2. On :

• Time : Day, Date (On Saturday, On May 1).
• Place : Street, On Main Street, On 1st Ave.

3. At :

• Time : At 8:00, At 7:30
• Place : Address (At 815 East Main Street)