in / on / at
Prepositions of place and time
The prepositions in, on, and at are very common English words. They are used when talking about a place or time. They have basic meanings and can be used in a wide range of situations.
So first, what do they mean?
As humans, vision is our strongest sense. Our brains are wired to visualize where things are. When speaking English, we visualize where things are in the English way.
We use in, on, and at to say where something is or happens.
- in a boundary: Where the area starts and ends IS important.
- on a surface: Where the area starts and ends IS NOT important.
- at a point in space
- at an event
Look at these examples and visualize where.
I’m in the supermarket.
He plays guitar in the bedroom.
I wash my hair in the shower.
I live in Texas.
They like wine in France.
I’m on the 4th floor.
Dinner is on the table.
The bus is on the road.
She reads books on the bus.
I work at the supermarket.
I’m at the bus stop.
We’re at yoga.
I’m at the concert.
We can’t see time, so we visualize when the same way as we visualize where.
We use in, on, and at to say when something is or happens.
- in: When the period of time starts and ends IS important.
- on: When the period of time starts and ends IS NOT important.
(We think of a day as being the time from when we wake up to the time we go to sleep. Exactly when a person wakes up and goes to sleep is not important.)
- at a point in time.
- at an event in time.
Look at these examples and visualize when.
I have breakfast in the morning.
She plays guitar in the afternoon.
I wash my hair in the evening.
We ski in winter.
They travel in spring.
We swim in summer.
We hike in fall.
Christmas is in December.
I finish high school in 2025.
I study English on Monday.
We celebrate the new year on December 31st.
We sleep on New Year’s Day.
I start work at 10am.
They have lunch at noon.
He walks the dog at sunset.
I sleep at night.
Think about what in, on and at mean and why they are used.
It may be very different to how you talk about time and place in you first language.
Many students find these prepositions confusing because the keep given rules for when to use each one. “You should say in the…” but “at the…” I think it is hard to remember all of these uses. And the thing is, they don’t happen all the time! We can say, “I work at a shop” or “I work in a shop”.
But when it makes sense, it is easier to remember. So the key is to change the way you think about prepositions. What does it mean? Does it clearly communicate the what I’m thinking?
Thinking about the meanings helps you see patterns and discover why we use these prepositions the way you do. When you think first about meaning and then explore how prepositions are used, you see why people are comfortable using them this way and it all makes a lot of sense.
With in and at the connection between place and time is quite clear.
- a room has walls, it starts at one wall and ends at the other. The next room is on the other side of the wall.
- a year has a start and end: it starts on January 1st and ends on December 31st. The next year comes after that.
- at refers to a point in space.
- at refers to a point in time.
On is a little more abstract.
When we look at objects we see the surface.
If we look at an apple, where does the surface of the apple start? It doesn’t have a clear start and end.
Think of the Earth. When we map it, we start with whichever place is most important for us and put it in the middle if we can.
We can put Europe and Africa in the middle.
We can put the Pacific in the middle.
Both maps show the surface of the Earth. There is no clear place where it has to start or end. This idea applies to the surface of any physical object.
Time is difficult because we can’t see time. But we can think about it in the same way.
When does a day start and end?
Now with digital clocks, the answer is 12:00 midnight. But the English language is older than this. The way we speak is based on people.
Think of a day. It is not clear when someone is going to start and end their day.
- Some people start their day early and finish early: 4:00 AM – 9:00 PM
- Others start and finish later: 10:00 AM – 1:00 AM. (Notice that even though they have gone past midnight, it is still one day, not two)
There is not time when someone’s day must start and end.
So, on fits well. And when we speak, on feels natural.
In everyday English, we say “on Monday” very often, so it just feels right. But, the basic meaning of on in this situation is the same as in any situation.
Uses of “on” are based on this idea: a surface – something that doesn’t have a clear start or end.
We also use on in other ways, on still has the same meaning:
Put a hat on. (Cover the surface of your head)
Come on! (Don’t stop now – no end yet!)
Last night Brian went on and on about American politics. (It seemed like there was no end)
People from different countries sometimes use different words. The important thing is that these words are not random.
There is logic behind both options.
In the USA people often say, “…on the weekend”.
In the UK people often say, “…at the weekend”.
Both are logical. They both make sense, so people are comfortable with whichever they are used to.
“What did you do on the weekend?“
“What did you do at the weekend?“
There are different words that people use.
- Sometimes these words have different meanings.
- Sometimes (like with on the weekend or at the weekend) either way makes sense and people simply use what they are used to.
Thinking about the core meanings of simple words like in, on, and at helps you understand how they are used.
I find it very strange that the traditional view is to “just remember” when to use in, on, and at. It is very hard to speak and use a language if you don’t have a sense of what the words mean.