How to Count in Korean: Two Number Systems and 15 Counters

Why does Korean have TWO ways to count? And why do you need different words for counting people, bottles, and slices?

Two Number Systems: Why?

Korean has two complete number systems: Native Korean (하나, 둘, 셋...) and Sino-Korean (일, 이, 삼... — borrowed from Chinese). You can't just pick one and ignore the other. Hours use Native Korean (한 시, 두 시, 세 시), but minutes use Sino-Korean (일 분, 이 분, 삼 분). Prices use Sino-Korean. Counting objects uses Native Korean with counters. Yes, it's confusing. Yes, you'll get used to it.

Think of it like English having 'first/second/third' (ordinal) vs '1/2/3' (cardinal) — except Korean's split is much bigger.

Native Korean Numbers (하나 to 열)

The first 10 Native Korean numbers: 하나(1), 둘(2), 셋(3), 넷(4), 다섯(5), 여섯(6), 일곱(7), 여덟(8), 아홉(9), 열(10). Important: when placed before a counter, some numbers shorten: 하나→한, 둘→두, 셋→세, 넷→네, 스물→스무. So it's 한 개, 두 개, 세 개, 네 개, not 하나 개.

Native Korean numbers are only used up to 99. Above that, use Sino-Korean.

Sino-Korean Numbers (일 to 십)

Sino-Korean numbers: 일(1), 이(2), 삼(3), 사(4), 오(5), 육(6), 칠(7), 팔(8), 구(9), 십(10). Bigger numbers build logically: 십일(11), 이십(20), 삼십삼(33), 백(100), 천(1000), 만(10,000). Used for: dates, money, phone numbers, minutes, months, addresses, and numbers above 99.

The 15 Essential Counters

Counters (단위 명사) are classifier words between a number and what you're counting. English has a few ('a GLASS of water', 'a SHEET of paper'), but Korean uses them for almost everything. The top 15: 개 (general items), 명/분 (people casual/polite), 마리 (animals), 권 (books), 잔 (cups), 병 (bottles), 장 (flat things), 대 (vehicles/machines), 벌 (clothing sets), 그릇 (bowls of food), 조각 (slices/pieces), 살 (age), 시 (o'clock), 분 (minutes), 원 (won/currency).

When in doubt, use 개 — it's the general-purpose counter that works for most objects.

Time: The Ultimate Mix

Telling time combines both systems in one phrase. Hours use Native Korean, minutes use Sino-Korean. 3:30 = 세 시 삼십 분 (se-si sam-sip-bun). Dates use Sino-Korean: 2024년 3월 15일 (i-cheon-i-sip-sa-nyeon sam-wol sip-o-il). Days of the month use Sino-Korean. Age typically uses Native Korean with 살: 스무 살 (20 years old).

Examples

커피 두 잔 — keo-pi du jan — Two cups of coffee

사람 세 명 — sa-ram se myeong — Three people

만 원 — man won — 10,000 won

세 시 삼십 분 — se-si sam-sip-bun — 3:30

책 다섯 권 — chaek da-seot gwon — Five books

스무 살 — seu-mu sal — 20 years old