Korean has two number systems with divided jobs. Native Korean (하나, 둘, 셋…) counts things, people, age and hours. Sino-Korean (일, 이, 삼…) handles dates, money, minutes and phone numbers. Yes, that means 3:30 uses both in one phrase: 세 시 삼십 분.
Every Korean learner hits this moment: you proudly count 일, 이, 삼 — and then hear someone order “맥주 두 잔” (two beers) with a completely different word for two. Nothing is wrong with your ears. Korean genuinely runs two parallel number systems, and the split is systematic, not random. Learn the split once and numbers stop being scary forever.
The two systems, 1–10
| # | 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) |
Why two? Native numbers are Korea’s original counting words; Sino-Korean numbers were borrowed from Chinese along with scholarly vocabulary. Both survived — with a clean division of labor.
Which system when?
| Use | System | Example |
|---|---|---|
| Counting things & people | Native | 사과 두 개 — two apples |
| Age (everyday) | Native + 살 | 스무 살 — 20 years old |
| Hours on the clock | Native + 시 | 세 시 — 3 o’clock |
| Minutes & seconds | Sino + 분/초 | 삼십 분 — 30 minutes |
| Money | Sino + 원 | 오천 원 — 5,000 won |
| Dates, years, months | Sino | 칠월 십오일 — July 15 |
| Phone numbers, math, floors | Sino | 삼 층 — 3rd floor |
A rough mental shortcut that covers most cases: if you could count it on your fingers, it’s probably native; if you’d read it off a screen, it’s probably Sino-Korean.
Counting bigger: 11 to 100 and beyond
Native numbers stack tens + units: 열하나 (11), 스물 (20), 서른 (30), 마흔 (40), 쉰 (50), 예순 (60), 일흔 (70), 여든 (80), 아흔 (90). In practice, native numbers above ~40 are rare — Koreans switch to Sino-Korean for large counts.
Sino-Korean builds like Chinese, perfectly regularly: 십일 (11 = ten-one), 이십 (20 = two-ten), 구십구 (99), 백 (100), 천 (1,000), 만 (10,000). Money runs on this system — 만 원 (10,000 won) is a bill you’ll handle daily in Korea.
The five shape-shifters
Before a counter word, five native numbers drop their final sound: 하나→한, 둘→두, 셋→세, 넷→네, 스물→스무. That’s why “one hour” is 한 시간, not 하나 시간, and 20 years old is 스무 살. It’s the single most common numbers mistake — and now it’s one you won’t make.
Counters: the words between number and noun
Like “two cups of coffee,” Korean counts through counter words. Four cover most of daily life:
| Counter | Counts | Example |
|---|---|---|
| 개 (gae) | things (general) | 가방 한 개 — one bag |
| 명 (myeong) | people | 두 명 — two people |
| 잔 (jan) | cups/glasses | 커피 두 잔 — two coffees |
| 마리 (mari) | animals | 고양이 세 마리 — three cats |
Korean numbers in three rules
- Native (하나둘셋) for counting, age and hours; Sino-Korean (일이삼) for dates, money and minutes.
- Time mixes both: 세 시 삼십 분 = 3:30.
- Five natives shorten before counters: 한, 두, 세, 네, 스무.
Drill both systems until they’re automatic
Reading a table is one thing — hearing 두 잔 vs 이 분 at native speed is another. Hanguljo teaches every number, counter and time word with native audio and locks them in with its 7-stage SRS, inside the full TOPIK 1–6 path.
Learn Korean with Hanguljo — FreeFrequently asked questions
Do I really need both systems as a beginner?
Yes, but it’s smaller than it sounds: 1–10 in each system plus the usage table above covers TOPIK 1 comfortably. Learn native 1–10 first (ordering, counting), Sino-Korean 1–10 the same week (prices, dates).
How does Korean age work now?
Since June 2023, Korea officially uses international age — the “Korean age” (+1 or +2) system is being phased out. Say your actual age with native numbers + 살.
Why is 16 pronounced “yungnyuk” and not “sib-yuk”?
Sound-linking rules: 십육 is pronounced 심뉵 (simnyuk). These shifts follow regular patterns you’ll absorb through listening — don’t memorize them from charts.
What about zero?
Two words, both Sino-Korean contexts: 영 (yeong) for math and scores, 공 (gong) for phone numbers — 010 reads 공일공.