동안/사이 – Korean Grammar vs Grammar #16

3 Speed Only

With Explanation

When we talk, we talk about time a lot. In Korean, 동안 and 사이 is used to tell the amount of time from one point to the other. Although they are usually interchangeable, there is some difference.

동안: long, 사이: short

First of all, 동안 is usually used when you want to emphasize that the period was long. 사이 is usually used if you want to say otherwise.

3시간 동안 참 많은 일들이 있었다.
3시간 사이 참 많은 일들이 있었다.
In 3 hours, there were many events.

If you say 3시간 동안, you felt that 3 hours were long. In contrast, you felt it was short if you say 사이.

내가 없는 동안 무슨 일이 있었던 거야?
내가 없는 사이 무슨 일이 있었던 거야?
What happened when I was not here?

If you want to say your absence was long, then you can use 동안 and you can use 사이 otherwise.

When it is blurry and we usually do so, you can use any of them. That's why I said earlier, both of them are usually interchangeable.

Only 동안

There is a grammatical difference. If the sentence is the combined sentence and the subject of the sentences are identical, then you should only use 동안 there.

집에 오는 동안 오늘 배운 것을 복습했다.
When coming back home, I reviewed what I have learned today.

I am coming back home and I am reviewing what I have learned. That's why 동안 is used here.

그녀는 영화를 보는 동안 종이 위에 수많은 것을 적었다.
When watching movie, she wrote a lot of things on the paper.

She watched movie and she wrote a lot of things, so it is 동안.

새 as 사이

When talking about 사이, sometimes it is shortened to 새. It is not a bird, it means time.

그 새를 못 참고 다 먹어 버린 거야?
You couldn't wait that short time and ate all of that?