Korean Numbers: Both Counting Systems Explained

The Sino-Korean number system is borrowed from Chinese characters. It handles large numbers, math, dates, money, and formal contexts. These numbers pair with specific counters like 월 (month), 분 (minute), 원 (Korean won), 년 (year), and 층 (floor).

When to Use Sino-Korean Numbers

You'll use Sino-Korean for shopping, scheduling, giving your phone number, and any formal communication. Master these to handle daily tasks smoothly.

Core Sino-Korean Numbers 1-10

• 일 (il) - one (1). Used for months like 일월 (January)
• 이 (i) - two (2). Example: 이분 후에 출발해요 (We depart in two minutes)
• 삼 (sam) - three (3). Example: 삼월에 벚꽃이 피어요 (Cherry blossoms bloom in March)
• 사 (sa) - four (4). Example: 사층에 올라가세요 (Go up to the 4th floor)
• 오 (o) - five (5). Example: 오분 기다리세요 (Please wait five minutes)
• 육 (yuk) - six (6). Example: 육월은 여름의 시작이에요 (June starts summer)
• 칠 (chil) - seven (7). Example: 칠천 원이에요 (It's 7,000 won)
• 팔 (pal) - eight (8). Example: 팔월에 휴가를 가요 (I vacation in August)
• 구 (gu) - nine (9). Example: 구백 원 할인이에요 (It's a 900 won discount)
• 십 (ship) - ten (10). Example: 십분이면 도착해요 (I'll arrive in ten minutes)

Larger Numbers and Key Terms

• 백 (baek) - hundred (100). Example: 이백 원이에요 (It's 200 won)
• 천 (cheon) - thousand (1,000). Example: 오천 원짜리 지폐예요 (It's a 5,000 won bill)
• 만 (man) - ten thousand (10,000). Example: 이 가방은 삼만 원이에요 (This bag is 30,000 won)
• 십일 (ship-il) - eleven (11). Example: 십일월은 가을이에요 (November is autumn)
• 이십 (i-ship) - twenty (20). Example: 이십분 후에 만나요 (Let's meet in 20 minutes)
• 영 or 공 (yeong/gong) - zero (0). Example: 제 전화번호는 공일공-이삼사오-육칠팔구예요 (My phone number is 010-2345-6789)

The Native Korean number system is Korea's original counting method. Use it for counting objects with counters, telling hours, and stating ages in casual speech. These numbers only go to 99. For 100 and above, always switch to Sino-Korean.

Shortened Forms for Numbers 1-4

Numbers 1-4 have special shortened forms used before counters. This rule is mandatory. Using the full form before a counter sounds incorrect to native speakers.

Native Korean Numbers 1-20

• 하나 (한) - one (1). Example: 커피 한 잔 주세요 (One cup of coffee, please)
• 둘 (두) - two (2). Example: 사과 두 개 주세요 (Two apples, please)
• 셋 (세) - three (3). Example: 세 시에 만나요 (Let's meet at three o'clock)
• 넷 (네) - four (4). Example: 네 명이서 갔어요 (Four of us went)
• 다섯 - five (5). Example: 다섯 시에 끝나요 (It ends at five o'clock)
• 여섯 - six (6). Example: 여섯 개 남았어요 (Six are left)
• 일곱 - seven (7). Example: 일곱 시에 일어나요 (I wake up at seven)
• 여덟 - eight (8). Example: 여덟 명이 왔어요 (Eight people came)
• 아홉 - nine (9). Example: 아홉 시에 문을 열어요 (It opens at nine)
• 열 - ten (10). Example: 열 개 있어요 (There are ten)

Numbers 11-20 and Beyond

• 열하나 - eleven (11). Example: 열한 시에 점심 먹어요 (I eat lunch at eleven)
• 열둘 - twelve (12). Example: 열두 시가 정오예요 (Twelve is noon)
• 스물 (스무) - twenty (20). Example: 스무 살이에요 (I'm twenty years old)
• 서른 - thirty (30). Example: 서른 살에 결혼했어요 (I got married at thirty)
• 마흔 - forty (40). Example: 마흔 살이 되었어요 (I turned forty)
• 쉰 - fifty (50). Example: 쉰 살이 넘었어요 (I'm over fifty)

Korean uses counter words (called classifiers) between the number and noun. This is similar to English phrases like 'a sheet of paper' or 'a glass of water.' Different objects require different counters based on their type or shape.

The General Counter

The most useful counter is 개 (gae), which counts general objects and things. Master this one first, and you can communicate about most everyday items.

Common Counters for Daily Life

• 개 (gae) - general objects. Example: 사과 세 개 주세요 (Three apples, please)
• 명 (myeong) - people (polite). Example: 다섯 명이에요 (There are five people)
• 마리 (mari) - animals. Example: 고양이 두 마리가 있어요 (There are two cats)
• 잔 (jan) - cups or glasses of drinks. Example: 커피 한 잔 마셨어요 (I drank one cup of coffee)
• 병 (byeong) - bottles. Example: 맥주 두 병 주세요 (Two bottles of beer, please)
• 권 (gwon) - books or volumes. Example: 책 세 권을 읽었어요 (I read three books)
• 장 (jang) - flat objects like paper and tickets. Example: 종이 한 장 주세요 (One sheet of paper, please)
• 벌 (beol) - sets of clothing. Example: 옷 두 벌 샀어요 (I bought two outfits)
• 대 (dae) - vehicles or machines. Example: 차 한 대가 있어요 (There is one car)

Special Counters with Sino-Korean Numbers

Most counters use Native Korean numbers, but these require Sino-Korean numbers:

• 분 (bun) - minute. Example: 삼십 분 걸려요 (It takes thirty minutes)
• 원 (won) - Korean won (currency). Example: 만 오천 원이에요 (It's 15,000 won)

Time and Age Counters

• 시 (si) - o'clock (Native Korean). Example: 지금 세 시예요 (It's three o'clock now)
• 살 (sal) - age in casual speech (Native Korean). Example: 스무 살이에요 (I'm twenty years old)
• 세 (se) - age in formal speech (Sino-Korean). Example: 이십 세입니다 (I am 20 years of age)
• 번 (beon) - times or occurrences (Native Korean). Example: 세 번 갔어요 (I went three times)

Mastering Korean requires the right study method, not just more hours. Research in cognitive science shows three techniques produce the best results: active recall (testing yourself rather than re-reading), spaced repetition (reviewing at scientifically-optimized intervals), and interleaving (mixing related topics rather than isolating one).

Why Passive Review Fails

Re-reading notes, highlighting textbook passages, or watching videos feels productive but produces only weak retention. Active recall (forcing your brain to retrieve information) strengthens memory pathways far more effectively than simple recognition. Flashcards demand active recall with every flip.

The Spaced Repetition Advantage

Pair flashcards with spaced repetition scheduling, and you learn in 20 minutes what takes hours of passive review. FluentFlash uses the FSRS algorithm to schedule every card at the exact moment before you forget it. This maximizes retention while minimizing wasted study time.

A Practical 3-Week Study Plan

1. Create 15-25 flashcards covering the highest-priority concepts
2. Review them daily for the first week using our FSRS scheduling
3. As cards become easier, intervals automatically expand from minutes to days to weeks
4. You're always working on material at the edge of your knowledge
5. After 2-3 weeks of consistent practice, concepts become automatic rather than effortful