At, In, On

 

Talking about time:

How to use “at”:

1. With clock times: at one o’clock, at 6.30, at 5.45 etc.

2. With points of time in the day: at midnight, at noon, at dawn, at sunset etc.

3. With holiday periods (meaning the few days around the holiday): at Christmas, at Diwali, at Easter etc.

4. With weekend: (British English) See you at the weekend; at weekend we go out.

 

How to use “in”:

1. With parts of the day: in the morning, in the evening, in the afternoon etc.

2. With months, seasons, years and centuries: in March, in the summer, in 2021, in the 21^st century etc.

 

How to use “on”:

1. With dates and specific days: on 3^rd March, on Friday afternoon, on the last day of the term etc.

2. With weekend: (American English) On weekends.

 

Talking about position and place:

How to use “at”:

1. With particular positions or places: at the end of the corridor, at the back of the room, at the corner of the street etc.

 

2. To mean next or beside: He sat at his desk. She stopped me at the door.

 

With words for buildings: at the airport, at the restaurant, at the theatre etc.

With city or place names, when you are talking about stopping during a journey: Does this train stop at Connaught Place?

 

But otherwise use “in”:

1. With a position or place, when something or someone is inside a larger thing such as a room: in the room, in the bath, in the kitchen, in the garden, in the doorway etc.

2. With cities, countries, states and conditions: He lives in Germany. When will you arrive in London? She is working in New York.

3. With the names of squares, plazas: in Time Square.

 

Use on:

With a position or place, when one thing is attached to or touching another: a spot on the end of her house. He hung his jacket on the back of a chair.

You can use either “in” or “on” with street names in British English; in American English, use “on”: in Oxford street (British English); on the High Street (American English).