- for a few years = 몇 년 동안 / 몇 해 동안 (both 년 and 해 mean "year") - for a few days = 며칠 동안 / 몇 날 동안 (날 also means "day", but 며칠 is more common) - a few years ago = 몇 년 전에 / 몇 해 전에 (전 = before, 후 = after) - a few days ago = 며칠 전에 / 몇 날 전에. 몇 is "how many" in questions (몇 달 걸렸어요? = How many months did it take?) and "a few" in statements. 며칠 is a contraction of "몇 일" (일 means "day"), but it has completely replaced the original, so it is the only correct form and "몇 일" is considered wrong spelling nowadays. But in all other cases it is [몇 + Noun], as in 몇 시간(how many/a few hours), 몇 날, 몇 년/해, and so on.