If you have ever tried to learn Korean numbers and felt your head spin, you are in excellent company. Korean has not one but two complete counting systems, and knowing which one to reach for is the difference between sounding natural and sounding like a beginner. The good news? Once you understand the logic behind the two systems, everything clicks into place. In this guide we will walk through both systems from the ground up, show you exactly when to use each one, and give you the counters, time expressions, and pronunciation tips you need to start using numbers with confidence.
Why Korean Has Two Number Systems
Korean uses two parallel sets of numbers: Native Korean and Sino-Korean. Native Korean numbers are the original, homegrown words the language developed on its own. Sino-Korean numbers come from Chinese and were borrowed centuries ago, which is why they will look familiar if you have studied Chinese numbers or Japanese numbers.
This might sound like double the work, but think of it more like having two tools for two different jobs. English does something similar in spirit: we say “two” but also “second” and “a pair,” choosing the form that fits the situation. In Korean, the choice between Native and Sino comes down to what you are counting or measuring. Master that one rule and the rest is mostly memorization.
Korean Numbers 1 to 10 in Both Systems
Let us start with the foundation: one through ten in both systems, written in Hangul with romanization to help your pronunciation.
| 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) |
Notice how the Sino-Korean numbers are shorter and crisper, usually a single syllable. That is one reason they are the system of choice for long strings of digits like phone numbers and prices. The Native numbers are a little longer and are used for smaller, everyday counting.
When to Use Each System (The Rule That Matters Most)
This is the heart of the whole topic. If you remember nothing else, remember this table. Sino-Korean handles anything that behaves like data: money, dates, phone numbers, minutes, addresses. Native Korean handles physical counting and human-scale things: objects, people, age, and the hour.
| Use case | System | Example |
|---|---|---|
| Money / prices | Sino-Korean | 3,000원 = 삼천 원 (samcheon won) |
| Dates (year, month, day) | Sino-Korean | May 5 = 오월 오일 (owol oil) |
| Phone numbers | Sino-Korean | 010 = 공일공 (gong-il-gong) |
| Minutes & seconds | Sino-Korean | 30 minutes = 삼십 분 (samsip bun) |
| Addresses & floors | Sino-Korean | 2nd floor = 이 층 (i cheung) |
| Counting objects | Native Korean | 3 apples = 사과 세 개 (sagwa se gae) |
| Counting people | Native Korean | 4 people = 네 명 (ne myeong) |
| Age | Native Korean | 20 years = 스무 살 (seumu sal) |
| The hour (time) | Native Korean | 3 o’clock = 세 시 (se si) |
A quick memory hook: if you could imagine reading it off a screen or a receipt, it is probably Sino-Korean. If you could touch it or point at it, it is probably Native Korean. Time is the famous exception that blends both, and we will get to that shortly.
Counting Beyond Ten: Tens, Hundreds, and Thousands
Native Korean tens
Native Korean has its own unique words for the tens up to ninety, then it stops. You will use these mostly for age and counting groups of things.
- 10 – 열 (yeol)
- 20 – 스물 (seumul)
- 30 – 서른 (seoreun)
- 40 – 마흔 (maheun)
- 50 – 쉰 (swin)
- 60 – 예순 (yesun)
- 70 – 일흔 (ilheun)
- 80 – 여든 (yeodeun)
- 90 – 아흔 (aheun)
To make numbers in between, simply combine: 21 is 스물하나 (seumul-hana), 35 is 서른다섯 (seoreun-daseot). There is no Native word for 100 in everyday use, so once you reach the hundreds you switch to Sino-Korean.
Sino-Korean tens, hundreds, and thousands
Sino-Korean is beautifully systematic. You build big numbers like Lego blocks by combining the base digits with place-value words.
- 10 – 십 (sip), 20 – 이십 (isip), 30 – 삼십 (samsip)
- 100 – 백 (baek), 200 – 이백 (ibaek)
- 1,000 – 천 (cheon), 3,000 – 삼천 (samcheon)
- 10,000 – 만 (man), 50,000 – 오만 (oman)
So 25 is 이십오 (i-sip-o), literally “two-ten-five.” And 137 is 백삼십칠 (baek-samsip-chil). Once you internalize the pattern, you can say any number into the millions without memorizing anything new. One thing to watch: Korean counts large numbers in units of 10,000 (만, man) rather than 1,000, so 100,000 is 십만 (simman, “ten ten-thousands”). This trips up learners at first, but it becomes second nature with practice.
Counters: The Little Words That Follow Numbers
When you count things in Korean, you almost always add a counter (also called a measure word) after the number. English does this occasionally too, as in “two slices of bread” or “three sheets of paper.” In Korean it is required, and the counter you choose depends on what you are counting.
- 개 (gae) – general objects: 사과 두 개 (two apples)
- 명 (myeong) – people: 학생 세 명 (three students)
- 분 (bun) – people, polite: 손님 두 분 (two guests)
- 살 (sal) – years of age: 서른 살 (thirty years old)
- 마리 (mari) – animals: 고양이 한 마리 (one cat)
- 권 (gwon) – books: 책 다섯 권 (five books)
- 병 (byeong) – bottles: 물 두 병 (two bottles of water)
Most counters take Native Korean numbers. Here is a small but important twist: the numbers 1, 2, 3, 4, and 20 change shape right before a counter. 하나 becomes 한, 둘 becomes 두, 셋 becomes 세, 넷 becomes 네, and 스물 becomes 스무. So “one cat” is 고양이 한 마리, not 고양이 하나 마리. It feels fussy at first, but these five short forms cover the vast majority of your counting, so they are well worth drilling early.
Telling Time: Where the Two Systems Meet
Telling time is the classic case where Korean mixes both systems in a single sentence, and it catches nearly every learner off guard. The rule is simple once you see it: hours use Native Korean, minutes use Sino-Korean.
- 시 (si) = “o’clock” → Native number
- 분 (bun) = “minutes” → Sino number
So 3:30 is 세 시 삼십 분 (se si samsip bun): “three” is Native (세), and “thirty” is Sino (삼십). Likewise, 7:15 is 일곱 시 십오 분 (ilgop si sibo bun). Remember the changed forms for the hour: 1 o’clock is 한 시, 2 o’clock is 두 시, 3 o’clock is 세 시, 4 o’clock is 네 시. Noon is 정오 and midnight is 자정, while 오전 (before noon) and 오후 (afternoon) work like a.m. and p.m.
Common Mistakes to Avoid
- Mixing up the systems. Saying your age with Sino numbers or a price with Native numbers is the most common slip. When in doubt, ask yourself: receipt or object?
- Forgetting to change 1–4 before counters. It is 한 개, not 하나 개. This one small habit instantly makes you sound more natural.
- Grouping large numbers in thousands. Because Korean groups by 10,000 (만), 30,000 is 삼만, not “삼십천.” Retrain your brain to think in units of man.
- Reading phone numbers as full numbers. Phone numbers are read digit by digit in Sino-Korean, and zero is 공 (gong), not the mathematical 영.
Pronunciation matters too. If you are still building your reading skills, spending time on family members in Korean and everyday Hangul vocabulary will make these number words far easier to say aloud. For deeper reference on counters and number rules, resources like How to Study Korean and 90 Day Korean are excellent companions to a structured course.
Practice Ideas That Actually Stick
Numbers reward little-and-often practice. Count the objects around you in Native Korean as you tidy up. Read prices aloud in Sino-Korean while shopping online. Set your phone clock to a random time and say it in Korean before you check. Say your friends’ ages, your bus number, your apartment floor. Because numbers appear in almost every real conversation, this kind of drilling pays off quickly and gives you a confidence boost you can carry into greetings, introductions, and even choosing Korean nicknames for the people you know.
If you enjoy comparing how different languages handle counting, you will notice Korean’s two-system approach is genuinely distinctive next to German numbers or Arabic numbers. That contrast is part of what makes learning Korean so rewarding.
Frequently Asked Questions
Do I really need to learn both Korean number systems?
Yes, but not all at once. Both systems are used daily and are not interchangeable, so eventually you will need both. Start with Sino-Korean 1–10 (it is simpler and more systematic) plus Native 1–10 for counting, then expand as you go. Within a few weeks the “which one?” question stops feeling like a decision at all.
Which system is used for age in Korean?
Traditional age uses Native Korean numbers with the counter 살 (sal), for example 스무 살 for twenty years old. Note that 20 uses its special counter form 스무 rather than 스물 here. In official contexts Korea also uses “international age,” but for everyday conversation the Native-number pattern is what you will hear most.
How do I tell time in Korean?
Use Native Korean numbers for the hour (with 시) and Sino-Korean numbers for the minutes (with 분). For example, 2:40 is 두 시 사십 분. This mix is the single most important time rule to memorize.
Why do the numbers 1 to 4 change before counters?
It is a pronunciation and grammar feature of Native Korean. Before a counter, 하나/둘/셋/넷 shorten to 한/두/세/네, and 스물 becomes 스무. So “two people” is 두 명, not 둘 명. These forms only appear in front of a counter, so once you learn them the pattern is very consistent.
How are Korean phone numbers read?
Digit by digit using Sino-Korean numbers, and zero is pronounced 공 (gong). So 010-1234 is read 공일공 일이삼사. You do not group them into “ten” or “hundred” units the way you might with a written figure.
Ready to move from memorizing numbers to actually speaking Korean? At The Cognitio, our expert tutors give you the guided practice and real conversation that turns rules like these into instant recall. Book a class with The Cognitio today and start counting, telling time, and chatting in Korean with confidence.