Numbers, time & counters

Korean has two number systems. The first one is the Sino-Korean number system, which comes from Chinese-based vocabulary. These numbers are used very often for prices, minutes, phone numbers, dates, floors, room numbers, and many formal counts.

The basic Sino-Korean numbers are 일 1, 이 2, 삼 3, 사 4, 오 5, 육 6, 칠 7, 팔 8, 구 9, and 십 10. After ten, the system is regular: 십일 is 11, 십이 is 12, 이십 is 20, 삼십 is 30, and so on.

For Vietnamese learners, this system is usually easier than native Korean numbers because it works very logically. If you know 삼 and 십, then 삼십 is simply 30. If you know 오 and 천, then 오천 is 5,000.

In real life, you will hear Sino-Korean numbers constantly when talking about money: 삼천 원, 오천 원, 만 원. You also need them for minutes, such as 삼십 분, meaning 30 minutes.

The second Korean number system is the native Korean number system. These numbers are used especially for counting people, objects, age, and hours on the clock.

The basic native Korean numbers are 하나 1, 둘 2, 셋 3, 넷 4, 다섯 5, 여섯 6, 일곱 7, 여덟 8, 아홉 9, and 열 10.

A very important point is that some native Korean numbers change shape before counters. 하나 becomes 한, 둘 becomes 두, 셋 becomes 세, and 넷 becomes 네. That is why Korean says 한 개, 두 개, 세 명, 네 시, not 하나 개 or 셋 명.

This is one of the first places where Korean feels different from English and Vietnamese. You do not just put a number before a noun. You usually need a counter, and the number may change before that counter.

Korean time expressions combine both number systems. Hours use native Korean numbers, while minutes use Sino-Korean numbers. This is why 3:30 is 세 시 삼십 분: 세 is native Korean, but 삼십 is Sino-Korean.

The word for hour on the clock is 시. Before 시, use the shortened native forms: 한 시, 두 시, 세 시, 네 시. For minutes, use Sino-Korean numbers with 분: 십 분, 이십 분, 삼십 분, 사십오 분.

To ask the time, Korean commonly says 몇 시예요?, meaning “What time is it?” The word 몇 means “how many / what number”. To answer, you can say 지금 세 시예요, meaning “It is three o'clock now.”

For half past, Korean uses 반, meaning half. So 세 시 반 means 3:30. This is more natural in daily speech than saying 세 시 삼십 분 every time.

Korean usually counts nouns with counters. A counter is a word that classifies the thing being counted. This is similar to saying “one cup of coffee” or “two pieces of paper” in English, but Korean uses counters much more often.

개 is a general counter for objects. If you do not know the specific counter, 개 is often the safest beginner choice. 명 is used for people in polite or neutral situations. 잔 is used for cups or glasses of drinks. 권 is used for books.

The common pattern is Noun + Number + Counter. For example, 사과 한 개 means one apple, 학생 세 명 means three students, 커피 두 잔 means two cups of coffee, and 책 네 권 means four books.

Remember that with native Korean numbers before counters, 하나 / 둘 / 셋 / 넷 become 한 / 두 / 세 / 네. This is why you say 책 네 권, not 책 넷 권.

부터 marks the starting point, and 까지 marks the ending point. Together, they create a range. This range can be about time, place, or even order.

For time, 아홉 시부터 다섯 시까지 means “from 9 o'clock to 5 o'clock”. For places, Korean can use 에서 for the starting location and 까지 for the destination, as in 집에서 학교까지, meaning “from home to school”.

A useful beginner pattern is Time부터 Time까지예요, meaning “It is from Time to Time.” For example, 수업은 아홉 시부터 열한 시까지예요 means “The class is from 9 to 11.”

Do not confuse 부터 with 에서. For time, 부터 is very natural. For a physical starting place, 에서 is usually more natural in beginner Korean.