At, in, and on are some of the most frequently used words in the English language, but sometimes, they are very easy to mix up!
Let’s make these words a bit more clear.
When we talk about location (where something is), we use all three of these words. Here’s a general rule for distinguishing (deciding) which one is right.
We choose at for a point in space.
- Where can I find the manager?
He’s at the front of the store.
In this case, we will have to go find the manager at the front (towards the entrance).
- I parked at the corner of Main Avenue and 1st Street.
This sentence explains that I have parked my car where Main Avenue and 1st Street (also known as 1st St.) cross.
We use in to describe being within a self-contained (closed in) area, also known as an enclosed space, such as a building, a room, or a fenced in yard.
- She’s in the library checking her email.
With this example, we can find this woman using the computer inside the library. Note that a person can be outside of the library, and still be at the library, but must be inside the building to be in the library.
- Oops, I left my money in the car!
This sentence would be used especially if I have parked my car and then walked into a restaurant or store. In this case, I would need to go back to my car to get money to pay.
We prefer on to talk about something that is located on top of or connected to a surface.
- The painting looks good on that wall.
This sentence describes a painting that is attached to the surface of a wall, where it looks nice.
- Be careful! There’s some dog poop on the sidewalk.
We use this expression to let someone know that he/she needs to be careful to avoid some dog poop that is on the ground.
How about when we talk about time? By the way for some great time idioms, click here.
We use at to describe exact times, either based on a clock, or the time of day.
- I will meet you at 10:30.
- I love walking on the beach at sunset.
We choose in to talk about longer periods of time, like months, years, and beyond.
- I will visit the U.S. in May.
- Top hats were popular in the 19th century (1800s).
And on is reserved for specific days and dates.
- I will see you on Thursday.
- Her birthday is on July 14th.
Note that we say, “Her birthday is on July 14,” in British English.
ETO American English teacher