🇰🇷 Lesson 6: Numbers, Time & Dates

Here is the one surprise this lesson has for you: Korean has two complete sets of numbers, and everyday life uses both. That sounds like double the work, but English does something similar. You say "one, two, three" and also "uni-, bi-, tri-" (unicycle, bicycle, tricycle). Korean's second set is simply used much more often. Once you know which set goes with which job, it stops being confusing and becomes a pattern you can rely on.

🔢 Sino-Korean Numbers (한자어 수)

Used for: dates, money, phone numbers, addresses, minutes, floors, and every number above 99.

Sino numbers are built like Lego: how many tens + ten + ones. So 35 is 삼십오 (three-ten-five), 247 is 이백사십칠, and this year, 2026, is 이천이십육. Two rules keep you accurate:

🔢 Native Korean Numbers (고유어 수)

Used for: counting with counters, hours on the clock, and age. Native numbers only go up to 99; above that, Koreans switch to Sino.

Teens are 열 + ones: 11 = 열하나, 15 = 열다섯. Twenties are 스물 + ones: 23 = 스물셋.

📏 Counters (단위) — This Lesson's Grammar

In English you can say "three books" directly. Korean always adds a counter (a unit word), the way English says "three cups of coffee" or "two sheets of paper" — except Korean does it for everything.

Look at 번: with Native numbers it counts how many times (세 번 = three times); with Sino numbers it is a label (삼 번 = number three). That one word is a perfect summary of the whole two-toolbox idea.

🕐 Telling Time

Clock time uses both systems at once: Native for the hour, Sino for the minutes. It feels odd for about a day, then it feels normal.

Keep 시 and 시간 apart: 두 시 is "two o'clock" (a point on the clock), while 두 시간 is "two hours" (a length of time).

📅 Days, Months & Dates

Days of the week all end in 요일. Months are just Sino number + 월, and dates are Sino number + 일.

Big to small: Korean dates run year → month → day, the same order as a Korean address. 2026년 4월 14일 = April 14, 2026. Useful time words: 오늘 (today), 내일 (tomorrow), 어제 (yesterday), 주말 (weekend).

📞 Phone numbers and age

Phone numbers are read digit by digit in Sino, usually with 공 for zero. The hyphen is often spoken as 에: 010-1234-5678 → 공일공에 일이삼사에 오육칠팔. Age in everyday speech uses Native + 살 (스물다섯 살); forms and formal documents use Sino + 세 (이십오 세).

🧩 Grammar in Action: Numbers + 이에요/예요

From Lesson 5 you know Noun + 이에요/예요 ("it is …"): 이에요 after a final consonant (받침), 예요 after a vowel. Numbers with counters behave exactly like nouns, so the same rule applies — just look at the last syllable:

To ask, use 몇 ("how many / what number") + counter, then 이에요/예요 with a rising voice: 몇 시예요? (What time is it?), 몇 살이에요? (How old are you?), 몇 명이에요? (How many people?), 몇 월이에요? (What month is it?). For days of the week, ask 무슨 요일이에요? For the date, ask 며칠이에요? — spelled 며칠, never "몇 일". The full set of question words arrives in Lesson 10; for now, these are handy fixed patterns.

💬 Dialogue: Making Plans

🌏 Culture Note — Age and the Number 4: Traditionally Koreans counted everyone as one year old at birth and added a year every New Year's Day ("Korean age"). Since June 2023 the law uses international age (만 나이) for official purposes, but you will still hear older counting in conversation, so don't be surprised if someone's "age" is one or two years more than you expect. Asking age early is normal, because it decides how people speak to each other (Lesson 13). And watch the elevator: 사 (four) sounds like the character for death, so many buildings label the 4th floor F instead of 4.

If you mix up the two systems a few times this week, good — that means you are actually using them. Every Korean learner says 삼 시 at least once. Mistakes here are just feedback about which toolbox to reach for.

✏️ Practice

🧠 Check Your Understanding

❓ Common Questions

🔮 Looking Ahead

So far every sentence you can build ends in 이에요/예요 — "it is …". In Lesson 7 you unlock verbs: the polite present ending -아요/어요 and the object marker 을/를, so you can say not only "it's three o'clock" but "I eat at three o'clock" and "I drink two cups of coffee".