Sino-Korean vs Native Numbers: Usage Rules
Korean has two number systems. Learn which one to use for time, age, counting, dates, and money.
Choosing between Sino-Korean (일, 이, 삼, ...) and native Korean (하나, 둘, 셋, ...) numbers is one of the most common rule confusions for learners. The split is not random — there are clear categorical rules. Sino-Korean for: dates, months, years, minutes, money, phone numbers, addresses, floors, grades. Native Korean for: hours, age, counting people and objects with counters.
A useful way to remember: 'when the number is the abstract part of a label' (date, price, room number), use Sino-Korean. 'When the number is concretely counting things' (how many cups, how old, how many people), use native Korean. The famous mixed case is time: 'three thirty' is 세 시 (native, for hour) 삼십 분 (Sino, for minutes). This mixed system makes telling time difficult for beginners but quickly becomes automatic with practice. Once the categorical rule clicks, the choice is no longer a guess but a quick lookup against the category.
고유어 숫자 (Native Korean Numbers) — When to Use
Use native Korean numbers (하나, 둘, 셋, 넷, 다섯…) for: hours (한 시, 두 시), age with 살 (한 살, 두 살), counting objects with most counters (한 개, 두 명, 세 잔). Note: 하나/둘/셋/넷 shorten to 한/두/세/네 before a counter.
한자어 숫자 (Sino-Korean Numbers) — When to Use
Use sino-Korean numbers (일, 이, 삼, 사, 오…) for: dates & months (일 월, 이 월), minutes (오 분, 십 분), money (천 원, 만 원), floor numbers (일 층, 이 층), phone numbers, and numbers above 99.