May 24, 2023

The Difference between 間に aida ni and うちに uchi ni – while in Japanese

The Problem

(あいだ)に and うちに both mean “while” or “during.” Sometimes they are interchangeable; sometimes they are not. Sometimes they are interchangeable but have a slightly different nuance. In today’s lesson, we’ll look at when to use which and present a number of example sentences.

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Both words are followed by the に particle. Let’s first look at the core words:

Surely the kanji is (うち) (within; inside)

but usually written in kana.



  • Both mean “while” or “during”.
  • Both imply a linear concept of time with a beginning and end.

When to use うちに

  • うちに is used with less certain time periods (the beginning and end aren’t clear or aren’t too important).


Let’s talk again in the near future.
[The time frame is ambiguous.]

Vocabulary & Notes

  • うちに might imply a sense of urgency in that the desired action may not be possible (or ideal) after the condition ends.


Please drink your tea while it's hot.
[There is a sense of urgency to enjoy the tea while it is still hot.]



While I’m still young, I’d like to go overseas.


  • In short, use うちに when the time period isn’t very clear & there is a sense of urgency to do the action before the state changes.

When to use (あいだ)

  • (あいだ)に is used when the time frame is clear or when the speaker wants to emphasize the timing.


Please come between 8 and 10.

[うちに wouldn’t work here because the timing is precise.]


  • In short, use (あいだ)に when there is a time frame that has a beginning and end, especially when the time frame is clear or the speaker wishes to emphasize the time frame.




うちに or (あいだ)に Both Okay

While in Japan, I’d like to go to Kyoto once.
[うちに emphasizes the time crunch (a visit to Kyoto can’t occur after one leaves Japan) while (あいだ)に simply states the fact]




うちに or (あいだ)

While it’s still bright out, let’s play basketball.



Before I realized it (while I was unaware), it got dark out.

[(あいだ)に wouldn’t work because there isn’t a beginning.]



I went shopping between 1 and 2.

[うちに wouldn’t work due to the clear time frame]


These two expressions are often used interchangeably, and depending on the specific context, their differences may not be very important. But to sum up the differences:


  • clear time frame
  • generally “while”


  • do something before the state changes
  • implies a sense of urgency
  • ambigious time frame

(あいだ)に is the most versitile, but there are also situations where only うちに is appropriate, especially when the exact timing of a state change is uncertain. As mentioned earlier, あついうちにお(ちゃ)()んでください。 (Please drink the tea while it's hot.) uses "うちに" because it's uncertain when the tea will cool down.

Makoto+ Members, click here to download all the sound files and PDF for this lesson. Practice makes perfect!

Sharing is caring!

  • That was great. I never understood the differences between these two words before! Thank you for the examples.

    • Great! Glad you liked it. Someone (Florian-san) suggested this on Instagram, I think. Let me know if you have other ideas for this kind of content.

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