At

x 1. At can indicate location
Example: The women are at the supermarket

x 2. At At indicates a place of attendance
Example: The children are at school

x 3. At can indicate in the direction of; toward
Example: The small boy threw a rock at the window

x 4. At is used to express time
Example: We are leaving at four thirty

x 5. At can mean busy using something; working
Example: I have been at the computer all day

x 6. At can indicate a condition
Example: Those two countries have been at peace for ten years

x 7. At can indicate reaction
Example: We were shocked at the condition of the classrooms

x 8. At indicates a degree of skill
Example: Your son is good at tennis, but not very good at hockey

x 9. At can indicate a rate or level
Example: Mary tries to buy everything at a discount

x 10. At can indicate the highest possible degree in value
Example: At least she comes to work every day


More examples

She was waiting me at the bus stop
We aren't allowed to watch television when we are at dinner
She is at a meeting
The teacher smiled at the new girl
They laughted at John
We are leaving at four thirty
They went home at midnight
We always eat lunch at noon
I've been at the cash register all night
That couple is really great at playing ping pong