Prepositions

Form

Used to specify when something happens.
(From general [in] to specific [at])

I was born in 1990.

The meeting is on Friday.

Let’s meet at 3 PM.


Meanings

A simple way to remember `in`, `on`, `at` for time.

  • IN (Largest Periods)
  • Centuries, Decades, Years, Seasons, Months
  • e.g., in the 21st century, in the 80s, in 2025, in summer, in July

  • ON (More Specific)
  • Days and Dates
  • e.g., on Sunday, on my birthday, on April 1st

  • AT (Most Specific)
  • Times, Festivals, Specific Moments
  • e.g., at 9:00 AM, at midnight, at Christmas, at the moment

Practice exercises