Prepositions of Time

Expressing WHEN something happens

Sections
Introduction

1. Definition & Core Meaning

Prepositions of Time tell us when an action happens. They connect a noun/pronoun to a point or period in time.

What is it?
Expressing WHEN something happens

2. Use Cases

WordMeaningExample
atA specific clock time or moment"We meet at noon." / "She wakes up at 7 AM."
onA specific day or date"I go to church on Sunday." / "Born on 3rd June."
inA longer period (month, year, season, century)"She was born in 1999." / "In July, it rains a lot."
sinceFrom a past point continuously until now"I have lived here since 2015."
forA duration or length of time"He studied for three hours."
duringThroughout the entire length of a period"I fell asleep during the movie."
byNo later than a specific time (deadline)"Submit it by Friday."
until / tillUp to a specific point in time"Wait until I get back."
beforeEarlier than a point in time"Call me before 9 PM."
afterLater than a point in time"We ate after the meeting."

3. When to Use It (Time Expressions/Signals)

[!NOTE]
Quick Rule: at → specific times | on → days/dates | in → months/years/seasons

4. How to Use It (Rules)

  • Use at with clock times and specific moments: at midnight, at noon, at the weekend
  • Use on with days of the week and calendar dates: on Monday, on 5th July
  • Use in with months, years, seasons, centuries: in March, in 2024, in summer
  • Use for with durations: for two hours, for a week
  • Use since with a starting point (requires perfect tense): since 2010, since Monday