Numbers two: 하나, 둘, 셋

These are the numbers Korean had before contact with Chinese writing, which is why they look nothing like day 8's set. They survived because they are the everyday counting words: how many apples, how many people, what hour, how old. They only go up to 99, and anything larger switches to the Sino-Korean set, which is one reason they belong with small, countable quantities. So the question is always what you are counting: objects, people, hours and years of age take these; dates, money, minutes and phone numbers take day 8's.

A number and its counter are said as a single unit, and the join wears away the ends of the first four numbers: 하나 loses its final vowel, and 둘, 셋 and 넷 lose their final consonant. 스물 (seumul), twenty, does the same, becoming 스무 (seumu) before a counter. The counter itself tells the listener what sort of thing is being counted, and the noun comes first, so 'five apples' is 사과 다섯 개, the reverse of English order. When you do not know the right counter, 개 covers most objects and people will understand you.

Counters exist partly because Korean nouns do not mark singular and plural the way English does: 사과 is apple or apples. The counter carries the number and says what sort of unit you mean, much as English says two cups of coffee or three sheets of paper, except that Korean does it even for people. 몇 asks the question in the number's slot, so 몇 명 and 두 명 have the same shape. The sound change in 몇 명 is the one you have heard since 감사합니다 on day 1: a stopped sound right before m or n turns into a nasal, here n.