하나 to 열 — counting things and people
Korean has two number systems running in parallel: native Korean and Sino-Korean (lesson 6). The native system is what you use to count things, count people, give your age, and tell hours of the clock. The first ten are: 하나 (1), 둘 (2), 셋 (3), 넷 (4), 다섯 (5), 여섯 (6), 일곱 (7), 여덟 (8), 아홉 (9), 열 (10). When you attach a counter (a measure word), the first four shorten: 하나 → 한, 둘 → 두, 셋 → 세, 넷 → 네.
The first ten — memorize as a chant
하나, 둘, 셋, 넷, 다섯, 여섯, 일곱, 여덟, 아홉, 열. Most Korean kids learn these as a rhyme. They behave just like English 'one, two, three…' — used for things you can pick up and count. After 10, native numbers continue (열하나, 열둘…) but they get unwieldy past about 20 and Korean speakers switch to Sino-Korean for big numbers.
Number + counter = how many
Korean uses counters (measure words) for almost every count. Pattern: noun + number + counter. The number comes BEFORE the counter, and after the noun. Common counters: 개 (general items), 명 (people), 마리 (animals). Examples: 사과 두 개 ('two apples', literally 'apple, two-things'), 학생 세 명 ('three students'), 개 네 마리 ('four dogs').
The first four shorten before counters
하나 → 한, 둘 → 두, 셋 → 세, 넷 → 네. So you say 한 개 (not 하나 개), 두 명 (not 둘 명), 세 마리 (not 셋 마리). 다섯 through 열 stay the same: 다섯 개, 여섯 명. Forgetting to shorten is one of the most common A1 mistakes — the long forms only stand alone when you're counting in the air ('one, two, three…') without a counter.
Age: X 살이에요
Age uses native numbers + the counter 살. 다섯 살이에요 = '(I'm) 5 years old'. 저는 일곱 살이에요 = 'I'm seven'. For 1, 2, 3, 4 it's 한 살, 두 살, 세 살, 네 살 — same shortening rule. (Adult Koreans switch to Sino-Korean 세 with the polite 이세요 when asking elders' ages, but at A1 you use native numbers + 살 across the board.)
Telling hours of the clock — 한 시, 두 시, 세 시…
Hours are also native: 한 시 (1 o'clock), 두 시 (2:00), 세 시 (3:00), 네 시 (4:00), 다섯 시 (5:00). The counter for hour is 시. 지금 두 시예요 = 'It's 2 o'clock now'. (Minutes use Sino-Korean — that's lesson 6.)
