place or position
At is used to talk about where something is or where something happens.
There was a staircase at the end of the hallway.
You often use at to mean ‘next to’ or ‘beside’.
He waited at the door.
You say that someone sits at a table or desk.
I was sitting at my desk, reading.
If you want to mention the building where something is or where something happens, you usually use at.
We had dinner at a restaurant in Attleborough.
He lived at 14 Burnbank Gardens, Glasgow.
In British English, you say that someone is at school or at university when you want to say that they study there.
He had done some acting at school.
After a year at university, Ben joined the army.
Speakers of American English usually say that someone is in school.
They met in high school.
➜ See school - university*
You say that something happens at a meeting, ceremony, or party.
The whole family were at the funeral.
They met at a dinner party.
At is also used to say when something happens.
You use at when you are mentioning a precise time.
At 2.30 a.m. he returned.
The train leaves at 9 a.m.
If you want to know the precise time when something happened or will happen, you can say ‘At what time...?’ but people usually say ‘What time...’' or ‘When...?’
When does the boat leave?
‘We’re having a party on the beach.' – ‘What time?’ – ‘At nine.’
You can say that something happened or will happen ‘at dawn’, ‘at dusk’, or ‘at night’.
She had come in at dawn.
It was ten o'clock at night.
However, you say that something happened or will happen ‘in the morning’, ‘in the afternoon’, or ‘in the evening’.
If something happens at a meal time, it happens while the meal is being eaten.
Let's talk about it at dinner.
You say that something happens at Christmas or at Easter.
She sent a card at Christmas.
However, you say that something happens on a particular day during Christmas or Easter.
They played cricket on Christmas Day.
In British English, at is usually used with weekend.
I went home at the weekend.
American speakers usually use on or over with weekend.
I had a class on the weekend.
What are you doing over the weekend?