Understanding the Differences: "At," "In" and "On"

The differences between the prepositions "in," "on" and "at" can be difficult for English learners to understand, especially if their native language uses only one word to express the same idea.

But knowing how to use them all effectively is essential no matter the situation or the person you're talking to; you can think of them as some of the "building blocks" of English communication.

So this article will focus on explaining them and providing you with plenty of examples to help you understand their differences. Let's get started!

How to use “in”

Starting with "in," it is used to describe something within a space.

It's important to remember that space can come in many forms. You may first think of things like a box, or a room in a house or a building. However, time can also be thought of as space, and so can other things you cannot touch, such as emotions. This will be easier to understand once we look at a few examples.

As we can see from these sentences, it is used for both three-dimensional spaces (the refrigerator) and for flat spaces (the yard).

In this example, the space we are discussing is the time period of one particular year.

This time, we are talking about the emotional "space" of love. If love is space, Jenny is inside of it.

Other examples

physical spaces

•in the bathroom

•in the house

•in the car

spaces of time

•in March

•in 2001

•in the morning

figurative spaces

•in a bad mood

•in trouble

•in style

How to use “on”

Let's continue to "on." It's used to describe an object contacting something. However, just like with the previous preposition, this contact can be physical (like a location or vehicle) or figurative (such as "belonging to" something).

The dog is resting on (contacting/touching) the bench.

Here, the speaker is riding (in contact with) a vehicle.

The coffee is (unfortunately!) in contact with the shirt.

Now let's look at being in contact with things that are not physical.

On is used to refer to a specific day.

Other examples

physical contact

• on the shelf

• on your head

• on a horse

figurative contact

• on my mind

• on time

• on the list

referring to specific dates and times

• on Easter

• on July 1

• on Sundays

How to use “at”

Next is "at." "In" refers to being within a space or time, and "on" is used when something is literally or figuratively in contact with something else. "At," on the other hand, refers to a specific point in space or time. Let's look at this in action through some example sentences.

Compare this with a similar sentence: "She's waiting for us in the lobby." The lobby is a bigger area, but "entrance" is a more specific point, so we use "at."

"At the moment" is another way of saying "right now."

Other examples

• at the restaurant

• at 5:30 p.m.

• the doctor's office

• at 100º

So instead of spaces or surfaces, think of "at" as a way to refer to points.

Indicating locations

Next, let's focus on using these prepositions to talk about places.

• At is used to describe places that are generally small or more detailed (at home, at my desk, at the bus stop)
• In describes large places or places for which there is only one (in Canada, in the bag, in his room)
• On is used to describe something contacting a surface (on the table, on the second floor, on my shoulder)

For example, "at home" treats home as a point on a map, not the inside of the house. "In his room," on the other hand, focuses on the interior space, not on the room's location.

The meeting place is a very specific location.

Here, Japan is a large, unique place, and the speaker is referencing singers within the country.

The book is in contact with the surface of the desk, so we use "on."

Expressing time

When expressing time, the difference between these words depends on the length of time you are describing.

• At is used for specific times (at 3 o'clock, at noon, at that time)
• On describes dates and days of the week (on Monday, on Christmas Eve, on May 3)
• In indicates a period of time, not only one point (in 2019, in winter, in 5 years)

So going from the shortest amount of time to the longest, the order is: at < on < in 

Wrap-up

No matter who you are speaking to or why you are studying English, understanding these three prepositions is very important.

Don't worry if the small differences are confusing to you now; you will gradually begin to sense their proper usage the more you listen to and speak English yourself. Because of how fundamental they are, you will be practicing them even without realizing it!

This article was adapted from an original written by Hiroe Hatfield.