Korean Counter 개월: How to Count months (duration)

Use Sino-Korean numbers with 개월 to count time periods.

The Rule

개월 is the counter for months (duration): time periods. In Korean, you can't just say a number + noun. You MUST use a counter word between them. This is like English "two SHEETS of paper" or "three CUPS of coffee" — except Korean does this for EVERYTHING. Even "three apples" needs a counter: 사과 세 개.

Why English Speakers Get It Wrong

English only uses counters for uncountable nouns ("a glass of water", "a piece of cake"). Korean uses counters for ALL nouns — even ones English counts directly. The second trap: Korean has TWO number systems. 개월 uses Sino-Korean (일, 이, 삼...) numbers. Using the wrong system is a common mistake that sounds immediately wrong to Korean ears.

How It Works

Pattern: Noun + Number + 개월 Sino-Korean numbers: 일(1), 이(2), 삼(3), 사(4), 오(5), 육(6), 칠(7), 팔(8), 구(9), 십(10) The counter 개월 comes right after the number. The noun can come before or after the number+counter, but before is more natural in conversation.

Real Examples

• 삼 개월 동안 공부했어요. (sam gaewor dongan gongbuhaeteoyo.) — "I studied for 3 months." [Duration, not calendar month] • 육 개월 후에 한국에 가요. (yuk gaewor hue hanguke gayo.) — "I go to Korea in 6 months." [육 = sino 6]

Common Mistakes

❌ Using native Korean numbers with 개월 ✅ Use Sino-Korean numbers: 삼 개월 동안 공부했어요. → 개월 always takes Sino-Korean numbers. Mixing number systems is one of the most common counter mistakes. ❌ Saying the number without a counter (e.g., "사과 세") ✅ Always include the counter: 삼 개월 동안 공부했어요. → Dropping the counter sounds incomplete in Korean, like saying "three of" without finishing the phrase in English.

Quick Tip

Start with the 5 most common counters: 개 (things), 명 (people), 마리 (animals), 잔 (cups), 병 (bottles). Once these are automatic, add 개월 to your toolkit. Practice counting things you see daily: "커피 두 잔", "사람 세 명". The more you use counters in real situations, the faster they become natural.

개월 = months (duration). Uses Sino-Korean numbers.

Examples

삼 개월 동안 공부했어요. — sam gaewor dongan gongbuhaeteoyo. — I studied for 3 months.

육 개월 후에 한국에 가요. — yuk gaewor hue hanguke gayo. — I go to Korea in 6 months.