Learn Grammar
Korean numbers — when to use 하나 (hana) and when to use 일 (il)
Korean has two sets of numbers. Learn which one to use for time, age, money, dates, phone numbers and counting things, and why 하나 becomes 한.
The short answer: Korean has two number systems. Native Korean numbers (하나, 둘, 셋) are for counting things and people, for hours, and for age with 살. Sino-Korean numbers (일, 이, 삼), which come from Chinese, are for minutes, money, dates and phone numbers.
So 3:30 is 세 시 삼십 분: a native number for the hour, a Sino-Korean number for the minutes.
You ask the time in Seoul. Someone says 세 시 삼십 분 (se si samsip bun). You know 삼 is three. But why is the first "three" 세? Because Korean uses two different number words in one phrase.
What are the two sets?
| Number | Native Korean | Sino-Korean |
|---|---|---|
| 1 | 하나 (hana) | 일 (il) |
| 2 | 둘 (dul) | 이 (i) |
| 3 | 셋 (set) | 삼 (sam) |
| 4 | 넷 (net) | 사 (sa) |
| 5 | 다섯 (daseot) | 오 (o) |
| 6 | 여섯 (yeoseot) | 육 (yuk) |
| 7 | 일곱 (ilgop) | 칠 (chil) |
| 8 | 여덟 (yeodeol) | 팔 (pal) |
| 9 | 아홉 (ahop) | 구 (gu) |
| 10 | 열 (yeol) | 십 (sip) |
| 20 | 스물 (seumul) | 이십 (isip) |
Sino-Korean numbers are easy to build. 11 is 십일 ("ten-one"). 20 is 이십 ("two-ten"). 35 is 삼십오 ("three-ten-five").
Is there one rule for everything? No. The National Institute of Korean Language says the choice comes from custom, and there is no single rule for all cases. But the common patterns below cover most of daily life.
Which one do I use?
| Situation | Number set | Example | Meaning |
|---|---|---|---|
| Hours (시) | Native | 세 시 (se si) | 3 o'clock |
| Minutes (분) | Sino-Korean | 삼십 분 (samsip bun) | 30 minutes |
| Age with 살 | Native | 열 살 (yeol sal) | 10 years old |
| Age with 세 | Sino-Korean | 이십 세 (isip se) | 20 years old (formal) |
| Money (원) | Sino-Korean | 오천 원 (ocheon won) | 5,000 won |
| Things (개) | Native | 사과 두 개 (sagwa du gae) | two apples |
| People (명) | Native | 세 명 (se myeong) | three people |
| Cups, glasses (잔) | Native | 커피 두 잔 (keopi du jan) | two coffees |
| Dates | Sino-Korean | 삼월 오일 (samwol oil) | March 5 |
| Phone numbers | Sino-Korean | 공일공 (gong-il-gong) | 010 |
Time is the famous mix: hours are native, minutes are Sino-Korean. A Korea Economic Daily language column says it plainly. Today, 시 is read only with native numbers, and 분 only with Sino-Korean numbers. People say 아홉 시 (9 o'clock) and 다섯 시 삼십 분 (5:30).
The same column gives a good tip. Small counts, up to about ten, usually sound natural with native numbers: 한 명, 두 개, 세 잔. For big numbers, Sino-Korean is the usual choice.
For age, the dictionary notes that 살 is mostly used after native numbers. 세 is used after Sino-Korean numbers. So 열 살 and 십 세 both mean "10 years old." 살 is everyday speech. 세 sounds formal, like on a form or in the news.
Why does 하나 become 한?
Native numbers 1 to 4 and 20 get shorter before a counting word.
| Alone | Before a counter | Example |
|---|---|---|
| 하나 | 한 (han) | 한 개 (one thing) |
| 둘 | 두 (du) | 두 시 (2 o'clock) |
| 셋 | 세 (se) | 세 명 (three people) |
| 넷 | 네 (ne) | 네 잔 (four cups) |
| 스물 | 스무 (seumu) | 스무 살 (20 years old) |
So you say 한 개, not 하나 개. And you say 스무 살, not 스물 살. The standard Korean spelling rules even use examples like 한 개 and 열 살.
Easy mistakes
- 일 시 instead of 한 시. For 1 o'clock, say 한 시 (han si).
- 하나 명 instead of 한 명. Before a counter, 하나 always becomes 한.
- June and October. Dates use Sino-Korean numbers, but two months change shape. June is 유월 (yuwol), not 육월. October is 시월 (siwol), not 십월.
- Zero. Korean has no native word for zero. The National Institute of Korean Language says to use 영 (yeong) or 공 (gong). In phone numbers, you will often hear 공.
- Money in thousands. Korean counts big numbers in groups of 만 (man, 10,000), not in groups of 1,000. So 10,000 won is 만 원, and 50,000 won is 오만 원. The spelling rules even space big numbers by 만.
Why does Korean keep two systems?
The two sets have different jobs. Native numbers feel personal and everyday. You use them for things you can see and count in your hand: cups, people, apples, your age.
Sino-Korean numbers work like a system. They are good for long numbers, prices, dates and measurements. The language column says Sino-Korean words often go with Sino-Korean numbers, and native words with native numbers.
But look at 시. It comes from a Chinese character (時), and it still takes native numbers. This is why the National Institute of Korean Language calls it custom, not a rule. Learn the common pairs, and soon they will sound natural.
Tip: At a café, you will use both sets in one sentence: 아메리카노 두 잔 주세요. 구천 원이에요? ("Two americanos, please. Is it 9,000 won?")
Quick check
- "Four o'clock" → 네 시
- "15,000 won" → 만 오천 원
- "I am twenty years old" (everyday speech) → 스무 살이에요.
Sources
- National Institute of Korean Language, Online Q&A — reading native and Sino-Korean numbers — korean.go.kr
- National Institute of Korean Language — Korean spelling rules (Hangeul Matchumbeop), Articles 43 and 44 — korean.go.kr
- National Institute of Korean Language, Urimalsaem dictionary — 살 — opendict.korean.go.kr
- Korea Economic Daily (Saenggeul Saenggeul) — "오시 삼십분"에 담긴 우리말 역사 한 토막 — sgsg.hankyung.com