A large number of students learning Korean are confused by Korean numbers. This may be because there are two different types of numbers, each of which is read and pronounced differently: Pure Korean numbers (하나, 둘, 셋……) and Chinese Korean numbers (일, 이, 삼……).

These numbers are not confusing on their own. However, the big question that many students have is when to use one or the other. This question is made even more difficult due to the fact that many Korean grammar books don’t provide a good explanation. Even more baffling is that there are several different standards governing the use of these numbers.

So what is a Korean student to do? Well, just have a look at this article and you will improve your understanding of Korean numbers, both in written and spoken contexts.

## Rule #1

You use Pure Korean numbers (하나, 둘, 셋……) when the number you are speaking about is less than twenty.

Examples:

• 사과 15개(열 다섯 개): 15 apples
• 연필 15개(열 다섯 개): 15 pencils
• 11시(열 한시): 11 o’clock

Note: Since there are only twelve hours on a clock, the hour is always less twenty. Therefore, Pure Korean numbers (하나, 둘, 셋……) are used.

## Rule #2

You use Chinese Korean numbers (일, 이, 삼……) when the number you are speaking about is greater than twenty.

Examples:

• 자동차 36대(서른 여섯 대): 36 cars
• 8일(8일): The 8th (of the month)

Note: Since dates can go up as high as 28, 30 and 31, they are treated as numbers greater than twenty.

• 811초(팔분 십일 초): 8 minutes and 11 seconds

Note: Since there are sixty seconds in a minute and sixty minutes in an hour, seconds and minutes are treated as numbers greater than twenty.

Exception:

While there are only twelve months in a year, we do not use Pure Korean numbers when speaking about months. This is because the names of the months in Korean are all proper nouns. Therefore, Koreans don’t count them, but instead just use a proper noun for each one.

Examples:

• 1월(일월): January
• 2월(이월): February
• 11월(십일월): November

## Rule #3

You use Pure Korean numbers (하나, 둘, 셋……) when it is possible to individually count the thing that you are speaking about.

Examples:

• 17명(열 일곱 명): 17 people
• 20대(스무 대): 20 cars
• 4개(네 개): 4 beans

## Rule #4

You use Chinese Korean numbers (일, 이, 삼……) when it is not possible to individually count the thing that you are speaking about.

Examples:

• 벌레 400마리(사백 마리): 400 bugs
• 8층(팔 층): The 8th floor

Note: While you can count your own building’s floors, it’s not really possible to count the floors of other people’s buildings. Therefore, it is considered to be uncountable in Korean.

Example:

• 7만원(칠 만원): 70 dollars

Note: While you can count your own money, you can’t really count other people’s money. Therefore, it is considered to be uncountable in Korean.

Example:

• 5일(오 일): 5 days

Note: While we can count the number of days that pass in our own life, we can’t really count the number of days that go by in other people’s lives. Therefore, they are also considered to be uncountable in Korean.

Example:

• 2007년(이천칠 년): The year 2007

Note: Being that years can range from zero to an essentially countless number, they are considered to be uncountable in Korean.

Exception:

Ages can range from less than twenty to greater than twenty. Therefore, you can use either Pure Korean numbers (하나, 둘, 셋……) or Chinese Korean numbers (일, 이, 삼……) to speak about your age. It’s really up to you. The important thing is that if you use Pure Korean numbers (하나, 둘, 셋……) you put after your age, and if you use Chinese Korean numbers (일, 이, 삼……) you put after your age. If you don’t want to use or at all, you can also just use Pure Korean numbers (하나, 둘, 셋……).

Examples:

• 21살(스물한 살): 21 years old
• 32세(삼십이 세): 32 years old
• 내 나이는 마흔 다섯이에요.: My age is 35

## Rule #5

You use Chinese Korean numbers (일, 이, 삼……) when referring to Arabic numerals (1, 2, 3……).

Examples:

• 유통기한은 6개월입니다(육 개월입니다): The expiration date is in 6 months
• 5 더하기 510이다(오 더하기 오는 십이다): 5 plus 5 is 10
• 3주가(삼 주가) 있어요.: There are 3 weeks

## Conclusion

In this article, we have looked at five rules and two exceptions for using Korean numbers correctly. Some students might think that they are pretty easy, while others might find them to be difficult. I’m actually in agreement with both opinions. Those five rules are in fact quite easy for Koreans, however, they are not at all easy for foreigners to master.

In any case, please don’t worry too much. Koreans are never actually taught about this in school. They just instinctively know about it. Believe me. I’m 100% sure that over 95% of Koreans don’t even think about these rules in their daily lives. So, there is no need to feel bad if and when you struggle with Korean numbers. Just re-read my article when you get a chance, practice them and you’ll find yourself getting better.

This is now my second article on Korean grammar and culture and I plan to write more soon. I hope this has been helpful for you. If you want to have a look at my previous article click here and be sure to check back soon for article number three.

Thanks for reading and see you soon!