Korean Counter Dal (달) and Gaewol (개월): Counting Months

What you'll learn

• Say durations of one to twelve months with both 달 and 개월.
• Pair 달 with native numbers and 개월 with Sino numbers, without mixing them.
• Tell a month name (삼월, March) from a month count (삼 개월, three months).
• Use the right counter for baby ages, contracts and subscriptions.
• Build "for", "ago" and "later" phrases with 동안, 전 and 후.
• Prerequisites: native and Sino numbers 1–12. Estimated time: 20 minutes.

Korean Counter Dal: the Essentials

The Korean counter dal (달) is the native Korean word for "month" used as a counter, and 개월 (個月) is its Sino-Korean partner. They count the same thing, a stretch of time measured in months, but each takes its own number system. The word 달 also means "moon", which is where the month meaning comes from.

The bracketed pronunciations show a regular sound change described in the 국립국어원 standard pronunciation rules: after a final [k] or [p], the ㄱ of 개월 becomes tense, close to ㄲ. The spelling never changes, and Revised Romanization still writes yuk gaewol.

Traditional Forms: 석 달 and 넉 달

For three and four months, Korean has two older native forms: 석 달 (three months) and 넉 달 (four months). 석 and 넉 are special forms of 셋 and 넷 that survive before a few units, and 달 is one of them. You will hear 석 달 often in speech and read it in novels. 세 달 and 네 달 are also used and understood, so beginners can rely on those.

Knowing the two lists is the first step; the second is placing them in a real sentence.

How Do You Use 달 and 개월 in a Sentence?

To use 달 or 개월 in a sentence, put the number and counter first, then add a time word such as 동안 (for), 전 (ago) or 후 (later). The counter phrase works like an English time expression.

• 여섯 달 동안 한국에 있었어요. "I was in Korea for six months."
• 석 달 전에 이사했어요. "I moved three months ago."
• 한 달 후에 다시 와요. "I'll come back in a month."
• 월세는 한 달에 오십만 원이에요. "The rent is 500,000 won a month."

To ask how long something takes, use 몇 ("how many") with either counter and the verb 걸리다 ("to take time"): 몇 달 걸려요? or 몇 개월 걸려요? Both mean "How many months does it take?". The suffix 째 adds "so far, running": 몇 달째 기다리고 있어요 means "I have been waiting for months now".

Every pattern above works with either counter, as long as each counter keeps its own number system.

Which Number System Does Each Counter Take?

달 takes native numbers and 개월 takes Sino-Korean numbers, with no exceptions. The pairing comes from the words themselves: 달 is a native Korean word, and 개월 is a Sino-Korean word built from the characters 個 and 月.

This matches the general split explained in Sino vs native Korean numbers: native numbers count, Sino numbers measure and label. 달 and 개월 are unusual because they let you choose, so the choice depends on the situation rather than on the counter.

Expert insight: if you hesitate, choose 개월 with a Sino number. Sino numbers are the ones you already use for money and dates, 개월 is never wrong in formal or written Korean, and it continues smoothly above twelve: 십팔 개월, 이십사 개월. The real question is which counter fits which setting.

Where Do You Hear 달 and Where 개월?

You hear 달 most in everyday conversation about short periods and 개월 in formal, written, medical and commercial settings. The difference is register, which means the level of formality a word belongs to.

Babies' Ages in Months

Babies' ages are a special case worth learning early. Korean parents and doctors count a baby's age in 개월 rather than in years: 생후 육 개월 means "six months after birth". The question 아기가 몇 개월이에요? ("How many months old is the baby?") gets an answer such as 칠 개월이에요. Many parents continue in months until about two years, for example 십팔 개월. Korea's Civil Act (민법) also allows the age of a child under one year to be expressed in months, which matches this everyday habit; the 살 counter takes over for older children.

One more word for "month", 월, is not a counter at all, and it causes the most common mix-up on this page.

Month Names Versus Month Counts

월 names a calendar month, while 달 and 개월 count how many months pass. 삼월 means "March", the third month of the year. 삼 개월 and 세 달 mean "three months", any three in a row.

One sentence can hold both: 삼월에 와서 석 달 있었어요 means "I came in March and stayed three months". To ask "which month?", say 몇 월이에요?, pronounced [며둴], with 월 and no counter. Note the irregular names 유월 and 시월: the counts keep the regular numbers, so six months is 육 개월, not 유 개월. The full list of names is in months in Korean, and the order of year, month and day is in Korean date format.

The month family also borders on counters for weeks, days and years.

What Does 달 Not Count?

달 and 개월 count only months. Other periods use their own counters, each with a fixed number system.

Four common time words built on 달 do not count either. 이번 달 (this month), 다음 달 (next month), 지난달 (last month) and 매달 (every month) point to a particular month. Note the spacing: 이번 달 and 다음 달 are two words, while 지난달 and 매달 are one.

See the 주 counter, the 일 counter for days and the 년 counter for each neighbour. A worked example shows several of these counters at once.

Why Does Korean Have Two Counters for Months?

Korean has two month counters because it keeps a native word and a Sino-Korean word side by side for many everyday ideas. 달 is the native word, and 개월 came in through Chinese characters (個 "unit" + 月 "month"), the same written channel that brought Sino numbers for dates and money. Over time each word settled into its own register, the level of formality a word belongs to.

The same pairing appears with years: native 해 (두 해, two years) and Sino 년 (이 년). With years, the Sino form has almost replaced the native one in daily speech. With months, both are still fully alive, which is why learners need both. Seeing both in real conversations makes the register difference concrete.

달 and 개월 in Two Short Conversations

At a phone shop. A customer asks 약정은 몇 개월이에요? ("How many months is the contract?"). The clerk answers in the formal, commercial register: 이십사 개월이에요. 첫 삼 개월은 할인돼요. ("It's twenty-four months. The first three months are discounted.") Every number here is Sino with 개월, because contracts are written documents.

At the park. One parent says 아기 귀엽네요. 몇 개월이에요? ("Your baby is cute. How many months old?"). The other replies 이제 열 달 됐어요. 십 개월이요. ("Ten months now. Ten months.") The parent first uses the warmer native 열 달, then repeats the age in the standard 개월 form. Both are correct, and switching like this is normal.

The phone-shop dialogue shows that 개월 is the safe choice for anything printed. The worked example below applies the same logic to a learner's own story.

Worked Example: a Year in Korea in Months

A learner describes a stay in Korea in three sentences.

1. 삼월에 한국에 와서 여섯 달 동안 한국어를 공부했어요. "I came to Korea in March and studied Korean for six months." 삼월 is a name (March); 여섯 달 is a count in conversation, so 달 with native 여섯.
2. 비자는 십이 개월짜리예요. "My visa is a twelve-month one." A document period, so 개월 with Sino 십이. The suffix 짜리 means "worth, lasting".
3. 조카는 이제 십사 개월이에요. "My nephew is now fourteen months old." A child's age, so 개월.

The checkpoint: in each sentence, the counter decides the number system and the setting decides the counter. Errors happen when either link breaks.

Common Mistakes and Fixes

• 삼 달 → 세 달 or 삼 개월. 달 takes native numbers.
• 여섯 개월 → 육 개월 or 여섯 달. 개월 takes Sino numbers.
• 삼월 (for "three months") → 삼 개월. 삼월 is March.
• 유 개월 → 육 개월. The irregular 유 belongs only to the month name 유월.
• 지난 달 → 지난달. 지난달 is one word; 다음 달 is two.
• 몇 월 걸려요? → 몇 달 걸려요? 몇 월 asks "which month?", not "how many months?".

Learners often assume 달 and 개월 differ in meaning. Actually they mean the same length of time; the difference is register and number system. The practice set checks all six points.

Practice Set

Say each answer aloud, then check below.

1. "two months" with 달
2. "two months" with 개월
3. Read aloud: 6월
4. Read aloud: 6개월
5. "for four months" (choose either counter)
6. Fix the error: 아기가 열 개월이에요.
7. "a month and a half"

Answers: 1. 두 달. 2. 이 개월. 3. 유월. 4. 육 개월. 5. 네 달 동안, 넉 달 동안 or 사 개월 동안. 6. 아기가 십 개월이에요. 7. 한 달 반.

If item 3 or 4 tripped you, reread the section on month names; if item 6 did, return to the number-system table.

What This Lesson Does Not Cover

This lesson covers counting months of duration. It does not teach the full calendar vocabulary (days of the week, seasons), how to say dates with 년, 월 and 일 together, or the counters for weeks, days and years in depth; each has its own lesson linked below. The usage notes on register describe standard Seoul Korean. Individual speakers vary in how often they choose 달 over 개월, so treat the setting table as a typical pattern rather than a fixed law.

What to Learn Next

Continue with weeks in the 주 counter, then years in the 년 counter. For calendar months, see months in Korean. The Time Counters section lists every period counter in order. With the Korean counter dal and its partner 개월 in place, durations of any length are within reach.

Frequently Asked Questions

Which is more natural, 달 or 개월? Both are natural, in different settings. In everyday conversation about short periods, 달 sounds warmer and more spoken: 두 달 동안 있었어요. On forms, contracts, notices and in medical or childcare contexts, 개월 is standard: 육 개월 계약. For periods above twelve months, 개월 is far more common, as in 십팔 개월.

How do I say "for six months" in Korean? Say 여섯 달 동안 or 육 개월 동안. 동안 means "for, during" and follows the time phrase. 여섯 달 동안 한국에 있었어요 means "I was in Korea for six months". Use 육 개월 in writing or formal speech. Do not say 육 달 or 여섯 개월, which mix the two number systems.

Why is June 유월 and not 육월? June is written and said 유월 because the ㄱ of 육 dropped out before 월 over time, and the spelling now follows that pronunciation. October works the same way: 시월, not 십월. The 한글 맞춤법 (Hangul spelling rules) record both as the standard spellings (Article 52). The month counts keep the regular numbers: 육 개월, 십 개월.

How do you ask a baby's age in months? Ask 아기가 몇 개월이에요? ("How many months old is the baby?"). Parents answer with 개월 and a Sino number: 칠 개월이에요 ("Seven months"). Many parents keep counting in months until about two years, so 이십 개월 is a normal answer. After that, ages switch to 살: 세 살.

How do I say "a month and a half" in Korean? Add 반 (half) after the counter: 한 달 반 means "a month and a half", and 일 개월 반 is the formal version. The same pattern works for other periods: 두 달 반 (two and a half months). 반 always follows the counter. For "about a month or two", say 한두 달.