Telling time is where Korea's two number systems collide in the open, and the hour is the half that surprises learners: clock hours use native numbers, not Sino. Three o'clock is 세 시, not ×삼 시. One o'clock is 한 시, using the same bound form 한 you'd use in 한 개 or 한 명. This page owns the hour — the counter 시, the numbers it takes, and the determiner forms — and hands the minute off to its own page, because right beside the native hour sits a Sino minute, and switching between them mid-sentence is the whole trick of the Korean clock.
Hours 1 to 12 in native numbers + 시
The counter for o'clock is 시, and it takes native numbers. Crucially, that means the determiner forms for the small numbers — 한, 두, 세, 네 — exactly as before a counter like 개 or 명.
| Time | Korean | Reading |
|---|---|---|
| 1:00 | 한 시 | han si |
| 2:00 | 두 시 | du si |
| 3:00 | 세 시 | se si |
| 4:00 | 네 시 | ne si |
| 5:00 | 다섯 시 | daseot si |
| 6:00 | 여섯 시 | yeoseot si |
| 7:00 | 일곱 시 | ilgop si |
| 8:00 | 여덟 시 | yeodeol si |
| 9:00 | 아홉 시 | ahop si |
| 10:00 | 열 시 | yeol si |
| 11:00 | 열한 시 | yeolhan si |
| 12:00 | 열두 시 | yeoldu si |
지금 세 시예요.
jigeum se si-yeyo
It's three o'clock now.
우리 아홉 시에 만나요.
uri ahop sie mannayo
Let's meet at nine o'clock.
Watch 11 and 12 especially. Eleven is 열한 시 (ten + the determiner 한), and twelve is 열두 시 (ten + the determiner 두) — the small-number reduction still applies inside the compound, so it's 열두 시, never ×열둘 시. Only the final unit switches shape.
Asking the time: 몇 시예요?
To ask "what time is it?" you use 몇 ("how many/what") in the number slot, exactly as you would to ask a quantity: 몇 시예요? The answer comes back with a native number.
지금 몇 시예요?
jigeum myeot si-yeyo
What time is it now?
수업이 한 시에 끝나요.
sueobi han sie kkeunnayo
Class ends at one o'clock.
Notice 한 시에 in that last sentence: the particle 에 ("at") attaches to the time to mark when something happens. 세 시에, 아홉 시에, 열두 시에 — "at three, at nine, at twelve." The 에 is how Korean pins an event to a clock time.
The clock is the dual-system showcase
Here is the reframing that makes the Korean clock click. A full time expression — say 3:10 — is not all one system. The hour is native (세 시) but the minute beside it is Sino (십 분). So a single glance at the clock forces you to switch number systems mid-breath:
세 시 십 분에 회의가 있어요.
se si sip bune hoeuiga isseoyo
There's a meeting at 3:10.
Read it slowly: 세 (native) 시 … 십 (Sino) 분. This is the most important habit in telling time, and it's why learning the hour and minute as separate skills pays off. This page has given you the native hour; the Sino minute is covered in full on the minute uses Sino numbers, and the reason each half takes the system it does is laid out on native or Sino, which counter takes which.
The determiner forms are the trap: 네 시, not ×넷 시
Because the hour uses native numbers, it inherits the native numbers' shape-shift, and the four small numbers must appear in their bound forms. The one learners fossilize wrong is four o'clock: it's 네 시, never ×넷 시, because 넷 → 네 before a counter. Drill this directly — it's the single most common time error.
네 시에 카페에서 봐요.
ne sie kapeeseo bwayo
Let's see each other at the café at four.
여덟 시 반에 일어나요.
yeodeol si bane ireonayo
I get up at half past eight.
If the 하나→한, 둘→두, 셋→세, 넷→네 reduction is still shaky, it's worth locking down on its own, because it governs every counted phrase, not just the clock — see the forms that change.
Hours only run 1 to 12 — there's no 스무 시 in speech
A limit English speakers don't expect: colloquial Korean clock hours run only 1 through 12. There is no ×스무 시 for "20:00" in ordinary conversation, because native numbers above twelve simply aren't used for the hour. To place a time in the day, you add a part-of-day word in front:
오후 다섯 시쯤 도착해요.
ohu daseot sijjeum dochakaeyo
I'll arrive around five in the afternoon.
So "8 PM" is 오후 여덟 시 (afternoon/evening + eight o'clock), not a 20-based reading. The part-of-day words (오전 "AM," 오후 "PM," 아침 "morning," 밤 "night") get their own page — see AM, PM, and parts of the day.
The one exception: formal 24-hour schedules — train timetables, military time, official announcements — do read the hour with Sino numbers: 십삼 시 (13:00), 이십 시 (20:00). This is a written/announcement register, not something you say to a friend. In everyday speech, always native 1–12 plus 오전/오후.
Midnight and noon: 밤 열두 시, 낮 열두 시
There's no colloquial "0 o'clock." Midnight is 밤 열두 시 (night twelve o'clock), and noon is 낮 열두 시 (day twelve o'clock) or simply 정오 (noon). "Twelve sharp" adds 정각.
어제 밤 열두 시에 잤어요.
eoje bam yeoldu sie jasseoyo
I went to bed at twelve last night (midnight).
회의는 열두 시 정각에 시작해요.
hoeuineun yeoldu si jeonggage sijakaeyo
The meeting starts at exactly twelve o'clock.
Common Mistakes
1. Using Sino numbers for the hour. The hour is native — this is the number-one time error for learners coming from Chinese or from Korean phone/money numbers.
- ✗ 삼 시에 만나요.
- ✓ 세 시에 만나요. — se sie mannayo — "Let's meet at three."
2. Saying ×넷 시 for four o'clock. 넷 must reduce to 네 before 시.
- ✗ 넷 시
- ✓ 네 시 — ne si — "four o'clock"
3. Leaving other small numbers in dictionary form. 하나·둘·셋 also reduce.
- ✗ 하나 시, 둘 시, 셋 시
- ✓ 한 시, 두 시, 세 시 — han si, du si, se si — "one, two, three o'clock"
4. Reading the minute with a native number. Native hour, but Sino minute.
- ✗ 세 시 서른 분
- ✓ 세 시 삼십 분 — se si samsip bun — "3:30"
5. Using a 24-hour native reading in speech. There's no ×스무 시 in conversation; use a part-of-day word.
- ✗ 스무 시에 봐요.
- ✓ 저녁 여덟 시에 봐요. — jeonyeok yeodeol sie bwayo — "Let's meet at eight in the evening."
Key Takeaways
- Clock hours take native numbers with the counter 시: 한 시, 두 시, 세 시 … 열두 시.
- The small numbers wear their determiner forms: 한·두·세·네 — high-value drill is 네 시 (not ×넷 시).
- 11 and 12 keep the reduction inside the compound: 열한 시, 열두 시 (not ×열둘 시).
- The clock is bilingual: native hour + Sino minute (세 시 십 분). Never run one system through the whole time.
- Hours run 1–12 only in speech; add 오전/오후 for the day-part. Midnight is 밤 열두 시, and 24-hour schedules switch to Sino (이십 시).
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Start learning Korean→Related Topics
- The Minute Uses Sino Numbers: 십 분, 삼십 분TOPIK 1 — Clock minutes take Sino-Korean numbers with the counter 분 — 오 분, 십오 분, 삼십 분 — so a full time like 두 시 이십 분 runs native for the hour and Sino for the minute in a single breath.
- Half, To, and Past: 반, 전, 후TOPIK 2 — The relational time words — 반 (half past), 전 (before/to), 후 (after), and 정각 (on the dot) — and why 전 assembles in Korean order: 세 시 오 분 전, never the English 'five to three'.
- AM/PM and Parts of the Day: 오전, 오후, 저녁TOPIK 1 — 오전 (AM) and 오후 (PM) come before the time in Korean, and everyday speech leans on day-part nouns — 새벽, 아침, 낮, 저녁, 밤 — that sound warmer than strict AM/PM.
- Native or Sino? Which Counter Takes WhichTOPIK 2 — The master rule for Korea's two number systems: if you could point and tally the things, use native numbers (개, 명, 마리, 시, 살); if it's an abstract unit, measure, rank, or calendar/clock unit, use Sino (분, 원, 년, 층, 인분). Plus the clash cases that break learners.
- The Forms That Change: 한, 두, 세, 네, 스무TOPIK 1 — The classic Korean-beginner rule: 하나·둘·셋·넷·스물 drop their ending and become 한·두·세·네·스무 the moment a counter follows — 한 개, 두 명, 세 마리, 네 시, 스무 살, never ×하나 개.