LEARN KOREAN (한국어) [GRAMMAR] #1

"FOR" A CERTAIN AMOUNT OF TIME (동안)

동안 is a very useful word that can be used to indicate how long an action occurs. It is typically placed after a duration of time, for example:

2분 - 2 minutes
2분 동안 - for 2 minutes

10분 - 10 minutes
10분 동안 - for 10 minutes

이틀 - two days
이틀 동안 - for two days

동안 can also be used to indicate that an action occurs "while" another action occurs.

Those can then be added into sentences to indicate how long one does something for. Notice also that no additional particle is added to 동안. One would think that 에 should be added, but it is not.

저는 10분 동안 걸었어요 - I walked for 10 minutes
저는 30분 동안 공부했어요 - I studied for 30 minutes

While the translation of "동안" in these examples is usually "for", in essence, what you are doing is stating "for that period of time." Understanding this will help you understand later usages of "동안". For example:

저는 10분 동안 걸었어요 - I walked for (a period of) 10 minutes
저는 30분 동안 공부했어요 - I studied for (a period of) 30 minutes
저는 이틀 동안 안 잤어요 - I didn't sleep for two days

Remember:

It doesn't matter if you use the word or the numeral when writing a number. However, typically the word is written when a pure Korean word is used with a counter like 개, 명, 번, 시간, 대, 살, etc. In situations where Sino-Korean numbers are written (for example, in the sentences above) it makes no difference if you write the numeral or the word.

Also remember that the spacing is different depending on if you write a numeral or a word. If writing the word, there should be a space between the number and the word. For example:

저는 십 분 동안 걸었어요

If writing a numeral, it doesn't matter if you include a space or not. Both are seen as acceptable:

저는 10분 동안 걸었어요
저는 10 분 동안 걸었어요