Korean has two parallel number systems, and which one you use depends on what you are counting. Not on formality, not on politeness — on the noun.
| System | Looks like | Used for |
|---|---|---|
| Sino-Korean | 일, 이, 삼, 사, 오 | Money, dates, minutes, phone numbers, addresses, floors, height, weight |
| Native Korean | 하나, 둘, 셋, 넷, 다섯 | Age, hours of the clock, and counting objects and people |
This lesson is the Sino-Korean set. The native set is 118, and the two of them collide most visibly in 126, where a single clock reading needs both.
The Sino-Korean numbers
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|
| 영 / 공 | 일 | 이 | 삼 | 사 | 오 | 육 | 칠 | 팔 | 구 | 십 |
Above ten it is pure arithmetic — the tens word, then the ones word, with no joining and no irregular forms:
| 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
|---|---|---|---|---|---|---|---|---|---|
| 십일 | 십이 | 십삼 | 십사 | 십오 | 십육 | 십칠 | 십팔 | 십구 | 이십 |
Note what is not there: 10 is 십, not 일십. The 일 is dropped in front of a place word, so 100 is 백 and 1,000 is 천 rather than 일백 and 일천. It comes back in the ones place — 21 is 이십일.
영 and 공 are both “zero”, and they are not interchangeable in practice: 공 is what you say in a phone number or a room number, 영 is what you say for a quantity or a score.
Why big numbers are hard
This is the part that stays difficult long after the digits are easy, and it is not a vocabulary problem. Korean groups large numbers in units of 10,000 (만), where English groups in units of 1,000. The digits are the same; the cuts fall in different places.
An English reader sees two hundred fifty-two million, and reaches for a word at the comma. A Korean reader sees 2억 5297만 5000, and reaches for a word at a boundary that has no comma on it at all. Until the regrouping is automatic, every large figure is an arithmetic problem rather than a reading problem.
The scale words themselves are few:
| Figure | Korean | English scale |
|---|---|---|
| 100 | 백 원 | |
| 1,000 | 천 원 | |
| 10,000 | 만 원 | |
| 100,000 | 십만 원 | |
| 1,000,000 | 백만 원 | million |
| 10,000,000 | 천만 원 | |
| 100,000,000 | 억 원 | |
| 1,000,000,000 | 십억 원 | billion |
| 1,000,000,000,000 | 조 원 | trillion |
The practical shortcut for prices: divide the won figure by 10,000 and read the 만. 35,000원 is 삼만 오천 원 — “three-万 five-thousand”. Once you stop translating through English millions, the numbers get much faster.
이 · 그 · 저 — this and that
Korean splits “that” in two, by whose side of the conversation the thing is on.
| 이 | 그 | 저 | |
|---|---|---|---|
| Position | close to the speaker | close to the listener | away from both |
| Thing (것 / 거) | 이것 / 이거 | 그것 / 그거 | 저것 / 저거 |
것 is the written form and 거 is what people say.
A: 이거 얼마예요? — How much is this? B: 천 원이에요. — It’s 1,000 won.
Grammar: -(으)세요
An honorific imperative — how you politely tell or ask someone to do something. It is the ending on 앉으세요 (please sit) and 주세요 (please give me), which means you have already been using it since 1A without it being named.
The choice is the familiar one: does the verb stem end in a consonant?
| -으세요 | -세요 |
|---|---|
| Stem ends in a consonant | Stem ends in a vowel |
| 읽다 → 읽으세요 [일그세요] | 주다 → 주세요 |
| 앉다 → 앉으세요 [안즈세요] | 공부하다 → 공부하세요 |
Note the linking in both bracketed readings — the stem’s 받침 slides into the 으, exactly as in 105.
| Verb | Conjugated | Sentence |
|---|---|---|
| 읽다 — to read | 읽 + 으세요 | 책(을) 읽으세요. |
| 앉다 — to sit | 앉 + 으세요 | 여기 앉으세요. |
| 보다 — to watch | 보 + 세요 | 한국 드라마(를) 보세요. |
| 먹다 — to eat | 먹 + 으세요 | 점심 먹으세요. |
| 주다 — to give | 주 + 세요 | (저에게) 명함(을) 주세요. |
The two pairs that depend on rank
Two of these verbs have a separate form used when the person receiving the action is senior to you. This is the same instinct as the titles in 106, applied to the verb instead of the name.
| Plain | Honorific | Meaning |
|---|---|---|
| 주다 | 드리다 | to give |
| 먹다 | 들다 → 드세요 | to eat / drink |
(부장님께) 명함(을) 드리세요. — Give your card to the department head. 책임님, 커피(를) 드세요. — Please have some coffee, 책임님.
들다 is a ㄹ-irregular: the ㄹ drops before -세요, giving 드세요 rather than 들세요. It is worth memorising as a fixed phrase, because 드세요 is what you will hear at every company lunch.
Phone numbers
Read digit by digit in Sino-Korean, with 에 for the hyphen and 공 for zero.
전화번호(가) 뭐예요? — What’s your phone number? 팔이이팔에 육칠사공이에요. — It’s 8228-6740.
Practice patterns
______은/는 얼마예요? — How much is ______? ______은/는 ______원이에요. — ______ is ______ won. ______을/를 주세요. — Please give me ______.
Work culture: Korean money
The won (원). Coins run 10 to 500, notes 1,000 to 50,000 — and every one of them carries a person or an object from the Joseon period, which makes the currency a reasonable short introduction to who Koreans consider important.
동전 — coins
| Coin | Reading | Design |
|---|---|---|
| 10원 | 십 원 | 다보탑 — the Dabotap pagoda |
| 50원 | 오십 원 | 벼 이삭 — a stalk of rice |
| 100원 | 백 원 | 이순신 장군 (1545–1598) |
| 500원 | 오백 원 | 두루미 — a crane |
지폐 — notes
| Note | Reading | Portrait |
|---|---|---|
| 1,000원 | 천 원 | 퇴계 이황 (1501–1570) |
| 5,000원 | 오천 원 | 율곡 이이 (1536–1584) |
| 10,000원 | 만 원 | 세종 이도 (1397–1450) |
| 50,000원 | 오만 원 | 신사임당 (1504–1551) |
Who they are
| Figure | Why they are on the money |
|---|---|
| 이순신 장군 | Admiral and national hero; his naval victories repelled the Japanese invasions of the 1590s. |
| 퇴계 이황 | Neo-Confucian scholar, on how to become fully human and how humans relate to the universe. |
| 율곡 이이 | Joseon Confucian scholar, also a politician and reformer. |
| 세종 이도 | King Sejong, fourth king of Joseon — and the creator of Hangul. |
| 신사임당 | Artist, writer, calligrapher and poet; mother of 율곡 이이. |
Two things worth noticing. 세종대왕 is on the 10,000원 note, which is the one you handle most, and he is there for inventing the alphabet you spent all of 1A learning. And the 5,000원 and 50,000원 notes are a son and his mother — 율곡 이이 and 신사임당 — which is not a coincidence anyone in Korea will need explained to them.
The deck lists approximate SGD values as at 19 January 2026 — 만 원 was about S$8.74. Those are left out here because they are the fastest-rotting thing on the slide; the point is the denominations, not the rate.