When to use “on” and when to use “in”

By Maeve Maddox

Nate asks: What are the proper usages of the words “in” and “on” in a sentence? I often confuse the two. Here are some examples: “The boat is in/on the water,” “We are in/on the planet,” “We’re going to the concert in/on July 1st.”

The use of prepositions in English is frequently idiomatic. General guidelines exist, but be prepared to learn individual expressions in which the preposition does not adhere to the guidelines.

In the case of the prepositions in and on, here are the most usual uses.


in mainly denotes “rest at”:

PLACE: He lives in the country. He lives in Chicago. (BUT, He lives at 2300 Wabash Ave.)
TIME: I’ll be there in an hour.
MANNER: The child ran down the steps in tears.
REFERENCE: In my opinion we need a referendum. They are happy in their marriage.


on indicates proximity and position above or outside:

PLACE: He sat on the fence.
TIME: He was not thinking well on that occasion.
REFERENCE: He asked my opinion on the matter.
CONDITION: We’ll hire him on your recommendation.

The examples given in the question:

We are on the planet.
We are going to the concert on July 1.


We are going to the concert in July.

As for the example about the boat, either is correct, according to what is meant:

The boat is in the water. (As opposed to being on dry land for the winter)
The boat is on the water. (Look at all those boats out there on the water!)

However, it would be unidiomatic to say The ship is in the ocean or in the sea, unless you mean that it has sunk. The ship is on the sea.

Related to the question of when to use in is that of when to use into. While in denotes the state of being “at rest” in a place, or at least being (in a sense) surrounded by something, into denotes motion towards:

The dog jumped into the water.
The children (who were already in the water) jumped in the water.

When deciding whether to use in or into, ask yourself if the person or thing you are talking about is moving from one place to another. If so, use into.

More about prepositions in later posts. Stay tuned!

136 Responses to “When to use “on” and when to use “in””

  • oxford

    Dear @nix
    It should be
    I am watching Spongebob on nickelodeon at so and so PM /AM

  • Maeve

    The idiom is “in December.”

    If you add the day, you would say, “on December 12.”

  • Temraz

    Should i say on December or in December?

  • Jenni

    Hi! A big organization uses “in section 1, 2, 3 and so on” on all their paperwork/forms that has multiple sections whenever they write an email. As what I understand, “on” is used to denote a position for surfaces or position just above or outside the area. I believe ‘on’ is more appropriate than ‘in’ whenever they refer to any sections on any paperwork. Could you please enlighten me? Thanks!

  • Mari

    I, sometimes, confuse the utilization of prepositions, but it is not because I do not know how to use them; it is rather a questioning of my proficiency with English as a second language. In my every day routine, I notice major grammatical errors committed by native English speakers, and tend to double and triple check myself. Posters such as these, help me to reinforce my understanding of the English lexicon and clarify any questions I may have. As a foreigner, I try harder than the rest to perfect my written and spoken English. Many thanks!

  • Rolf Lange

    When referring to reports that contain maps and figures, is it correct to say: “As shown in Figure 3” or “As shown on Figure 3”?

  • Ritu

    Which is correct
    Assembly would be conducted in the back lawn.
    Assembly would be conducted on the back lawn.

  • Howard

    What will you do on winter vacation.

    On –> the scope is “upcoming”
    In –> the scope is “during”

  • Yassar

    I’m a little bit confused on the use of “in” and “on” at the same time. Take for example: 1. He will continue to linger on in darkness. 2. i don’t want any unprofessional doctor to be in on my case.

  • Jamie

    Hi. I’m still a bit confused on the use of “in” and “on”.

    Which is correct;
    What will you do in winter vacation?
    What will you do on winter vacation?

  • Jose G Medina

    Hi there:
    Thanks for the explanation, but what about, in/on a car or a train, or an airplane, or a motorcycle?

  • Maddy

    What is the logic behind statements like “sitting in a car/taxi” and “sitting on a bus”? Any grammar rule to say so? If yes please do share.

    Thanks in advance.

  • LucĂ­a

    I have a question
    Is it correct to say San Francisco is on the West Coast of The United States or is it San Francisco is in the West Coast of The United States??

    Please help me

  • faith

    Thanks for the proper usage of in and on .But can u please help me to understand well how to use in and on ? Because frankly speaking,sometimes i was confused how to used that !

    I hope you will help me.
    Thank you and God speed!

  • Prasad

    I too bungle up my write-ups every time I confront this situation.
    …originated in the land or
    …originated on the land

  • nix

    when should i use in or at?

    ex. im watching spongebob in/at nickelodeon?

    im still confuse..

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