Korean Numbers and Time: How to Tell Time in Korean & the Two-System Split

하나 · 일 — two words for the number one, both completely Korean.

Part of the Korean Grammar — Make Sense of It, Not Just Memorize series — start there if you’re new.

The Question Every Learner Eventually Asks

Sooner or later, usually right around the time the clock enters the picture, a learner stops mid-sentence and asks some version of the same question. One student, mid-lesson: “For the 12 o’clock, do we use Native Korean?”

It’s the right question, and this whole guide is the answer. Korean runs two complete number systems side by side. Native Korean (하나, 둘, 셋 ha-na, dul, set) is the original count. Sino-Korean (일, 이, 삼 il, i, sam) came from Chinese characters centuries ago, the way English absorbed Latin. Both are 100% Korean, neither is “more correct,” and they’ve divided up the everyday jobs between them.

The clock is where the two systems collide inside a single phrase — which is why time is where most number mistakes surface. So this guide does numbers and time together, in one place: both systems in full, the counters that decide between them, the clock, dates, money, and how the numbers actually sound out loud. Along the way I’ll flag the specific spots where real learners stall — drawn from actual lessons, not invented for the article.

Native = counting things, people, age, the o’clock hour. Sino = dates, money, minutes, phone numbers, anything past 100.

Native Korean: 1 to 10, and the Wall at Six

Number	Native Korean	Romanization	Before a counter
1	하나	ha-na	한 (han)
2	둘	dul	두 (du)
3	셋	set	세 (se)
4	넷	net	네 (ne)
5	다섯	da-seot	다섯
6	여섯	yeo-seot	여섯
7	일곱	il-gop	일곱
8	여덟	yeo-deol	여덟
9	아홉	a-hop	아홉
10	열	yeol	열

Two things in this table deserve more attention than textbooks give them.

First, the wall at six. Learners reliably rattle off 하나 through 다섯 and then slow to a crawl. It isn’t imagination — 여섯, 일곱, 여덟, 아홉 are longer, sound similar, and arrive in lessons after the easy momentum is gone. The six–seven–eight cluster is one of the most re-drilled stretches of the number line: one learner mixed up 여섯 and 여덟 while telling time; another needed repeated passes through 다섯 개 to 여덟 개 before the run held. If you budget extra repetition anywhere in the native numbers, budget it here.

Second, the short forms. When a native number sits directly in front of a counter, the first four shrink: 하나 → 한, 둘 → 두, 셋 → 세, 넷 → 네 (and 스물 → 스무 at twenty). 하나 시 or 둘 명 isn’t just informal — it’s wrong to Korean ears. The shrink carries through compound numbers too: twelve o’clock is 열두 시 yeol-du si, never 열둘 시, because the 둘 hiding at the end still contracts.

Above ten, native Korean stacks like English teens: 열하나 (11), 열둘 (12) … 열아홉 (19), then dedicated tens words — 스물 (20), 서른 (30), 마흔 (40), 쉰 (50), 예순 (60), 일흔 (70), 여든 (80), 아흔 (90). It stops at 99; there is no native word for one hundred. And a practical honesty note: in casual Seoul speech, native numbers thin out above about fifty — for big counts people quietly slide to Sino-Korean.

Sino-Korean: Say the Math Out Loud

Number	Sino-Korean	Romanization
1	일	il
2	이	i
3	삼	sam
4	사	sa
5	오	o
6	육	yuk
7	칠	chil
8	팔	pal
9	구	gu
10	십	sip

Above ten, Sino-Korean is pure arithmetic: eleven is “ten one” (십일), thirty is “three ten” (삼십), forty-three is “four ten three” (사십삼). No new words until 백 baek (100), 천 cheon (1,000), and 만 man (10,000).

That last one, 만, is where English speakers stumble on prices. Korean groups large numbers in ten-thousands, not thousands. A 30,000-won meal is 삼만 원 sam-man won — “three ten-thousands” — never “삼십천.” Even learners who know the rule assemble big prices one block at a time at first: a price like 33,000 won (삼만삼천 원) genuinely takes a beat to build. That beat is normal. The blocks get faster; the grouping never changes.

One more pair worth flagging because learners mix them by ear: 칠 (7) and 팔 (8). They’re short, similar syllables sitting next to each other — and they get swapped the same way six and eight get swapped on the native side. If you keep confusing a specific pair, you’re not bad at numbers — you’ve just found your pair. Drill the pair, not the whole list.

The Counter Words Decide Everything

Korean almost never counts a bare number. You say “two cup-units of coffee” — 커피 두 잔 keo-pi du jan — and that little unit word, the counter, is what tells you which number system to use.

Counter	Counts	System	Example
개 gae	objects	Native	사과 네 개 — four apples
명 myeong	people	Native	세 명 — three people
살 sal	age	Native	스무 살 — twenty years old
시 si	o’clock hour	Native	네 시 — four o’clock
잔 jan	cups	Native	두 잔 — two cups
마리 ma-ri	animals	Native	한 마리 — one animal
권 gwon	bound volumes	Native	책 한 권 — one book
분 bun	people (polite)	Native	두 분 — two people (respectful)
분 bun	minutes	Sino	삼십 분 — thirty minutes
원 won	money	Sino	오천 원 — 5,000 won
월 wol	months	Sino	삼월 — March
일 il	day of month	Sino	팔일 — the 8th
층 cheung	floors	Sino	삼 층 — third floor

The intuition that covers most of the table: if you can point at it, pick it up, or look it in the eye, it’s native. If it’s a number stamped on a sign, a price tag, a clock’s minute display, or a calendar, it’s Sino. (Phone numbers read digit by digit are Sino too: 010 is 공일공 gong-il-gong.)

Yes, 분 appears twice in that table, and the two are spelled and pronounced identically. 두 분 du bun is “two people, respectfully” — native number, used for teachers, elders, customers (a restaurant host asks 몇 분이세요? — “how many in your party?”). 이 분 i bun is “two minutes” — Sino number. The counter’s job, not its spelling, decides the system, and this pair is the proof. Its sibling 명 myeong is the neutral people-counter: 학생 세 명 for three students, but 선생님 두 분 for two teachers.

And here’s the counter detail that surfaces constantly in real speech: the same number changes meaning with the counter. 세 개 se gae is three things; 세 시 se si is three o’clock. Learners produce one while meaning the other more often than any textbook admits — mid-conversation, “three (things)” and “three (o’clock)” blur, because English lets bare “three” do both jobs. Korean never does. The counter is not decoration; it’s the meaning.

As for why animals take 마리 and books take 권 — there’s no rule to extract. The pairings are conventional, the way English says “a loaf of bread” but “a bar of soap.” Memorize counters as chunks (커피 한 잔, 고양이 두 마리, 학생 세 명), say each aloud ten times, and stop asking why. For counters, stored chunks beat derived rules — this is the one corner of Korean grammar where “just memorize it” is the sophisticated strategy, not the lazy one.

How to Tell Time in Korean: Both Systems in One Breath

Now the collision. The hour takes native Korean; the minutes take Sino-Korean. Always, in that order, and it never flips.

세 시 삼십 분 se si sam-sip bun → 3:30 — three (native) o’clock, thirty (Sino) minutes

This is why 12 o’clock is 열두 시 yeol-du si and not 십이 시 — the answer to the question at the top of this page. 십이 is Sino-Korean; it’s exactly right for 십이 분 (12 minutes) and wrong for the everyday hour. Same digit, different counter, different system.

Three real stall points, from real lessons:

Eleven and twelve. Learners whose first language treats “eleven” as a single word meet 열한 시 (10+1 o’clock) and need an extra assembly step — one learner repeated 한 시 through 열 시 smoothly, then stalled at 열한 시 on first meeting it. The compound is the hurdle, not the hour. Helpfully, the everyday spoken clock only runs 1–12, so 열한 시 and 열두 시 are the only two compounds you need to automate.
The mid-phrase switch. Saying a duration like “one hour and six minutes” — 한 시간 육 분 — forces you to switch systems inside one phrase: 한 (native) for the hour-length, 육 (Sino) for the minutes. Learners visibly gear-shift at that seam. The stall isn’t forgetting; it’s the hand landing on the wrong shelf and correcting. It gets shorter every time.
시 vs 시간. 시 marks a point (세 시, three o’clock); 시간 measures a length (세 시간, three hours). Confusing “thirty minutes” with “three hours,” or a clock time with a duration, is a regular classroom event — the words look close and English “hour” covers both. One question separates them: am I naming a moment or measuring a stretch?

The useful extras, quickly: 반 ban (“half”) replaces 삼십 분 — 세 시 반 = 3:30, friendlier and shorter. 오전/오후 (AM/PM) come before the hour: 오후 세 시 = 3 PM. Noon is 정오, midnight is 자정, and the dark hours (roughly 1 to 5, though usage varies by speaker) are 새벽 sae-byeok, not “morning.” For “sharp,” add 정각: 세 시 정각 = three o’clock on the dot. And to ask the time: 지금 몇 시예요? ji-geum myeot si-ye-yo — “what time is it now?”

Exception worth knowing: the 24-hour clock of train stations, the military, and broadcast announcements uses Sino hours (십삼 시 for 13:00). For everyday 1–12 conversation, native is the form Koreans expect.

Dates: The Sino Side’s Home Turf — With Two Traps

Months and days are Sino-Korean, full stop. March 8th is 삼월 팔일 sam-wol pal-il. But two traps live here, and learners walk into both:

Trap one: native numbers leaking into months. After drilling native numbers hard, learners overproduce them — November comes out as “열한월” instead of 십일월 sip-il-wol. It’s a completely logical error (the clock just taught you 열한!), and it’s still wrong: months never take native numbers. If the word ends in 월, reach for Sino.

Trap two: the two irregular months. June is 유월 yu-wol (not 육월) and October is 시월 si-wol (not 십월) — the final consonant drops so the word flows. Every other month is regular. Learners assembling dates syllable by syllable — 십일일 (the 11th), 십이일 (the 12th), 십삼일 (the 13th) — are doing it right; the assembly just needs reps before it stops feeling like arithmetic homework.

How the Numbers Actually Sound

Numbers are where learners first collide with the gap between Korean spelling and Korean sound. Three number-specific pronunciation notes save a lot of confusion:

여덟 ends in a silent ㅂ. The spelling shows a double final consonant (ㄼ), and learners predictably try to pronounce both — “yeo-deop.” Standalone, 여덟 is already [여덜] yeo-deol; the ㅂ stays silent. Naming the rule explicitly — “don’t read the ㅂ, treat it as an ㄹ ending” — has locked it in for learners on the spot. It’s a one-sentence fix hiding behind a scary spelling.

아홉 attracts a phantom Y. A surprisingly common slip: 아홉 a-hop drifting to “ya-hop” — one learner produced the slide three times on a single vocabulary slide. If you catch yourself gliding into the vowel, restart from a clean 아. Like most pronunciation slips, it tends to stop once it’s named out loud.

Nasalization changes what you hear. (Full rule, with place names and the double-shift words, in our guide to Korean nasalization.) When a stop consonant (ㅂ, ㄷ, ㄱ) meets a nasal (ㅁ, ㄴ), the stop goes nasal too — spelling unchanged. For numbers this matters constantly: 십만 (100,000) is pronounced [심만] sim-man, 백만 (1,000,000) is [뱅만] baeng-man, and 십육 (16) is pronounced [심뉵] sim-nyuk — that last one surprises learners who assembled a careful “sip-yuk” and hear something else entirely from Korean speakers. You’ll never see these written differently; they live only in the mouth. If prices in the hundred-thousands slide past your ear, you were listening for a ㅂ the rule already deleted.

Practice: Where the Two Systems Meet

Say each answer out loud before checking. Feel where the system switch happens.

12:30 → 열두 시 삼십 분 (or 열두 시 반) — native hour with the contracted 두, Sino minutes
“Three cups of coffee, please.” → 커피 세 잔 주세요 — counting things is native; 셋 shrinks to 세
8:15 → 여덟 시 십오 분 — and 여덟 is pronounced [여덜]
A 33,000-won bill → 삼만삼천 원 — Sino, grouped in 만 blocks
November 11th → 십일월 십일일 — months and days are Sino; no 열한월
“I’m 22 years old.” → 스물두 살이에요 — age is native; 둘 shrinks even inside the compound. (이십이 살 would be understood, but it sounds like reading your age off a passport — for age, native numbers are what make you sound like a person rather than a document.)
16 (reading the number aloud) → 십육, pronounced [심뉵]
3 PM → 오후 세 시 — the AM/PM word comes first
“Three hours” vs “three o’clock” → 세 시간 vs 세 시 — length vs point
9:45 → 아홉 시 사십오 분 — clean 아 in 아홉, no phantom Y

FAQ

Is 십이 시 ever correct for 12 o’clock?

In everyday speech, no — the form is 열두 시. Sino hours appear only in the 24-hour system of stations, broadcasts, and the military (십삼 시 for 13:00). What’s always correct with 십이 is 십이 분 (12 minutes), because minutes use the opposite system.

Why is one o’clock 한 시 but one minute 일 분?

The hour and the minute answer to different systems inside the same clock reading. Hours take native (한 시); minutes take Sino (일 분). Read 1:01 aloud — 한 시 일 분 — and the switch happens mid-phrase, every time.

How high should I learn native numbers?

Solid through the twenties for daily life (age, counting, the clock). They technically run to 99, but above fifty casual speech leans Sino anyway, and at 100 native stops entirely — 백 and up are Sino-only.

Do I have to memorize which counter takes which system?

Mostly it follows the touch-it/read-it intuition: touchable things, people, age, and the o’clock hour go native; measurements, dates, money, and anything on a sign go Sino. For the pairings that don’t feel intuitive, memorize the chunk (한 잔, 두 마리, 세 명) rather than the rule — chunks are what fluent speakers are running on anyway.

Why do I keep hearing “sim-man” for 십만?

Nasalization: a stop 받침 before ㅁ or ㄴ turns nasal, so 십만 is always pronounced [심만] — by news anchors as much as by fast talkers. The spelling never changes; the sound always does. Expect [심만], [뱅만], [심뉵], and fast speech gets slower.

Two systems sounds like double the work, but it’s one small decision on repeat: am I counting something I can touch, or reading something off a sign? Hours, ages, and cups go native. Minutes, dates, and money go Sino. Get that reflex and 몇 시예요? stops being a quiz — it’s just a question you can answer.

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This lesson was planned, reviewed, and edited by Teacher Seoul, with AI-assisted drafting. Corrections are welcome via the Contact page.