One of the most difficult aspects of English for beginners is mastering the different uses of in, on, at.
Luckily for you, there are some general rules that almost always work. However, I warn you, there are exceptions to these rules, just like there are for most rules in any language. Don’t stress out about the exceptions, just accept them and learn them.
“In” is used to describe someone or something’s location when they are within something with borders, barriers, or walls.
So, let’s brainstorm. What has borders, barriers, or walls?
Excellent, excellent. We can use these to make some examples of sentences with “in”.
I’m in my room.
She’s in the library.
He was working out in the gym.
They’ll be in class.
Simple stuff, right?
“On” is used to describe someone or something’s location when they are on a horizontal or vertical surface.
What are things that are horizontal or vertical surfaces?
So, what are some examples we could use with these surfaces?
He is standing on the floor.
They are lying on the bed.
I am running on the lawn.
She sat in the chair.
Easy to understand.
“At” is the most difficult to understand, in my opinion. You will definitely need to listen to a lot of examples of it before you can fully understand how to use it.
Many English teachers will say that “at” is used to describe specific locations, but I do not agree with that at all. Yes, it describes a specific location, but not specifically where you are at in that location.
Is that a little confusing?
Let’s think of some examples of locations first.
With all of these examples we could use “at”.
I’m at the park.
She was at the mall.
They’ll be at the university for a few hours.
Now, when I say I’m at the stadium, this does not mean I am in the stadium. I could be in the stadium, or I could be at the entrance of the stadium, or I could be 2 blocks away from the stadium, or maybe I’m in a helicopter hovering above the stadium. When I say I’m at the stadium, I am giving my general location.
In all of those examples, I could have given a more specific location like, I am in the stadium, or I am standing in front of the entrance, or I am two blocks away from the stadium, or I am hovering above the stadium. “At” just gives my general location.
Is that clear to you?
Two instances where English learners use “at” are with work and home. Many students forget this or don’t know this and will tell me, “I’m in home.”, or, “I’m in work.”
NO, NO, NO!
For both of these, you must use at. I’m at home and I’m at work. Do not ask me why, it is just the way it is.
Two Interesting Exceptions
Sometimes you will hear English speakers say, “I’m sitting in my chair.”, and you will ask me, “Why not on?”
In this case, we can use “in” or “on” for chairs with armrests and/or a back. The armrests and/or back act as borders/boundaries that allow us to use “in” with these chairs.
Chairs without armrests or back, we will always use “on”
The last interesting case for you to think about and know is bed. You will hear English speakers say, “I’m in my bed.”, and you will ask me, “Why not on?”
In this case, we use “on” when a person is lying, sitting or standing on the bed. As soon as a person gets underneath the blankets, this person is now in the bed because the blankets act as borders/boundaries. That person is now within the bed.
You should be at least a little less confused about the uses of in, on, at. If it is still unclear, you can always ask a question below. At the same time, my best advice is to listen, and read as much possible in order to experience as many examples of in, on, at. In this way, you will naturally begin to understand how to use in, on, at.