Lesson

In, at, on

Place prepositions

≈ 15 min 8 block(s)

Text

Using in, at, on

Prepositions in, at, and on are used to describe time and place. Choosing the correct preposition depends on scale (large vs. small), specificity (general vs. exact point), and conventional expressions.

  • Use 'in' for larger periods (months, years, long periods) and for enclosed spaces.
  • Use 'on' for days, dates, and surfaces.
  • Use 'at' for specific points in time and precise locations (addresses, exact points).

Table

Reference: In / At / On — time & place

Preposition Use Example
in Months, years, seasons, long periods, enclosed spaces The report was published in July. / She works in the office.
on Days, dates, surfaces, streets, specific days The meeting is on Monday. / The papers are on the desk.
at Exact times, specific points, addresses, events The call is at 9:00 AM. / Meet me at 123 Main Street.

Tip

Key rule: Match scale and specificity

Decide how specific you need to be and choose the preposition that matches that level of detail:

  • If it's a long period or an enclosed area → use 'in'.
  • If it's a surface, day, or date → use 'on'.
  • If it's a precise time or a single point/location → use 'at'.

Remember conventional exceptions: 'at night', 'in the morning', 'on the weekend' (varies by dialect)

Example

Examples in context

The conference is in June.

We have a meeting on Tuesday at 2 PM.

Please send the documents to the office at 45 King Street.

She works on the third floor in room 305.

Tip

Common mistakes

Watch out for these universal errors when choosing in, at, or on:

  • Mixing time and place rules (e.g., using 'in' because it feels spatial for a day).
  • Using 'at' with months or long periods (should be 'in July', not 'at July').
  • Using 'on' with exact times (use 'at 3 PM', not 'on 3 PM').
  • Confusing surface vs. point: 'on the list' (surface) vs. 'at the entrance' (point).

If unsure, ask: Is it a long period, a day/date/surface, or a precise point?

Quiz

Choose the correct sentence:

Hint: Think about which preposition we commonly use with days.

Quiz

Complete: The meeting is _____ 3 PM.

Hint: Think about which preposition we use with exact clock times.

Quiz

Choose the correct sentence:

Hint: Think about whether the location is a point or an area.

Key Points

GrammarPoint

in

preposition CEFR A1 //ɪn//

Used for months, years, seasons, long periods, and enclosed spaces.

The project starts in September.

GrammarPoint

on

preposition CEFR A1 //ɒn//

Used for days, dates, surfaces, and streets.

The deadline is on Friday.

GrammarPoint

at

preposition CEFR A1 //æt//

Used for exact times, specific points, addresses, and events.

The interview is at 10 AM.

Vocabulary

corner

noun CEFR A2 //ˈkɔːrnər//

The point where two streets or edges meet.

Let's meet at the corner of Elm and 3rd.

Vocabulary

office

noun CEFR A1 //ˈɒfɪs//

A place where business or professional work is done.

I will be in the office all afternoon.

Vocabulary

weekend

noun CEFR A2 //ˈwiːkˌend//

The end of the week, usually Saturday and Sunday.

We will review the report on the weekend.