-(으)ㅁ Nominalizer: Meaning, Rules and Examples

What you'll learn

• Build the -(으)ㅁ noun from vowel stems, consonant stems, ㄹ-stems and the main irregular stems.
• Recognise common nouns that were made this way, such as 꿈, 잠, 삶 and 웃음.
• Read and write note-style lines such as 숙제를 확인함.
• Avoid errors such as 살음, 어렵음 and 기쁘음.

Prerequisites: the -기 nominalizer (-기 nominalizer) and the idea of a verb stem (verb stems). Time: about 15 minutes.

Listen to the two model sentences for this lesson.

The next section defines the ending and shows it inside two lines.

What Is the -(으)ㅁ Nominalizer?

The -(으)ㅁ nominalizer is the ending that makes a noun out of a verb or an adjective in written Korean. A nominalizer is an ending that lets a whole verb or adjective behave like a noun, so it can take particles (small words such as 이/가 and 을/를). Some results are ordinary words that every learner meets, such as 꿈 ("dream") and 웃음 ("laughter"). Others are made on the spot in notes, forms and formal prose, such as 확인함 ("checked").

The -(으)ㅁ noun usually names a result, a state or a feeling, not an activity in progress. Compare 기쁨 ("joy", a feeling) with 기뻐하기 ("being glad", an activity). That is the main difference from the -기 noun, and the comparison section below returns to it.

A First Example

The first line is a normal spoken sentence, because 웃음 has become a regular noun. The second line is note style: the line stops on the -(으)ㅁ noun, with no 이다 or polite ending. The next section shows how to build the form from any stem.

How Do You Form -(으)ㅁ?

The -(으)ㅁ form is built by adding ㅁ after a vowel and 음 after a consonant. The stem is the verb without the final 다. The table covers the stem types that learners ask about.

Three patterns need a closer look.

ㄹ-stems keep their ㄹ. In front of ㄴ, a final ㄹ drops (살다 gives 사는). In front of ㅁ it does not drop. It stays as the first half of the final cluster ㄻ, so 살다 gives 삶 and 알다 gives 앎. In speech the cluster sounds like a single [ㅁ], so 삶 is [삼]. The Hangul Spelling Rules (한글 맞춤법, Article 19) say to keep the stem visible when 음/ㅁ makes a noun, which is why 만듦 keeps the ㄹ.

A few older nouns use 음 after ㄹ. 울음 ("crying"), 얼음 ("ice") and 졸음 ("drowsiness") come from 울다, 얼다 and 졸다. They are separate dictionary nouns, so learn them as words and do not copy them as a pattern.

Irregular stems rebuild first. The ㅂ of 어렵다 turns into 우 before a vowel, so the noun is 어려움. The same happens in 아름다움 ("beauty", from 아름답다) and 즐거움 ("pleasure", from 즐겁다). The ㄷ of 걷다 turns into ㄹ, so the noun is 걸음. These stem changes match the polite ending, as explained in ㅂ irregular and ㄷ irregular.

The next section builds a note-style line step by step.

Worked Example: Building 다음 회의는 금요일에 하기로 함

To write the line "We decided to hold the next meeting on Friday" as a meeting note, start from a normal sentence and change only the ending.

1. Start from the spoken sentence. The speaker would say 다음 회의는 금요일에 하기로 했어요.
2. Find the final verb. The last word is 했어요, from 하다 ("do").
3. Take off the polite ending. The stem is 하-, and the decision pattern -기로 하다 stays in front of it.
4. Add ㅁ. 하 ends in a vowel, so 하 + ㅁ gives 함.
5. Write the line. 다음 회의는 금요일에 하기로 함.

You'll know it worked when the line ends on a noun and still reads as a full statement. In minutes and memos the reader supplies the missing "was". The same shape works for the past: 숙제를 확인했음 means "Homework was checked", with the past marker 았/었 in front of ㅁ.

The next section lists the places where the form appears.

Where Is -(으)ㅁ Used?

The -(으)ㅁ form is used in four settings: notes and forms, labels and ratings, titles, and formal written clauses. All four are written or semi-written. Conversation uses -기 or -는 것 instead.

1. Notes, minutes and forms. A line ends on the noun to save space: 참석함 ("attended"), 확인함 ("checked"), 해당 없음 ("not applicable"). The last example is common on application forms. Spoken: 없음 sounds like [업씀].

2. Labels and ratings. Public displays use the noun for a state. A common air-quality scale reads 좋음 ("good"), 보통 ("normal"), 나쁨 ("bad") and 매우 나쁨 ("very bad"). The nouns 좋음 and 나쁨 come from the adjectives 좋다 and 나쁘다.

3. Titles and credits. A book cover often says the author's name followed by 지음, from 짓다, which here means "to write". The line 홍길동 지음 means "written by Hong Gildong".

4. Formal written clauses. A whole clause can become a noun phrase with a particle after it. 그가 왔음을 알았다 means "I learned that he had come". The clause 그가 왔음 is the object of 알았다, and 을 marks it. Spoken, it sounds like [그가 와쓰믈 아랃따]. In newspapers and reports, patterns such as -(으)ㅁ으로써 ("by doing") are common: 매일 연습함으로써 실력이 늘었다 means "By practising every day, my skill improved".

An informal online style also ends sentences on ㅁ, as in 재미있었음 ("it was fun") or 갔다 왔음 ("I went and came back"). Learners may read it in reviews and posts, but it is not standard writing and is best kept for reading.

The next section separates the nouns that have become ordinary words.

Which -(으)ㅁ Nouns Are Now Ordinary Words?

Many -(으)ㅁ nouns are ordinary dictionary words, and their verbs are not always obvious. The Standard Korean Dictionary (표준국어대사전) lists them as nouns. Learn them as words, and notice that several pair with their own verb.

Three of these are cognate objects: the noun and its verb come from the same root, as in 꿈을 꾸다, 잠을 자다 and 춤을 추다. English has the same habit in "dream a dream".

걸음 and 걷기 are different words. 걷기 is the -기 noun and names the activity: 걷기는 건강에 좋아요 ("Walking is good for health"). 걸음 is the -(으)ㅁ noun and names one step or a pace: 걸음이 빨라요 ("Her pace is fast"). The same pair exists for other verbs, so check the dictionary before you replace one with the other.

The next section compares -(으)ㅁ with the two nominalizers you have already met.

How Is -(으)ㅁ Different from -기 and -는 것?

The -(으)ㅁ noun gives a result or state in writing, while -기 names an activity or plan and -는 것 names a fact or thing. The choice depends on style first and meaning second.

A short rule helps. If you are writing a note, a form or a formal report, -(으)ㅁ is a good fit. If you are speaking or writing a friendly message, use -기 for activities and -는 것 for facts. The full comparison, with more verbs, is on -기 vs -는 것 vs -(으)ㅁ. The related lessons are -기 nominalizer and -는 것 nominalizer.

The copula has its own nominal forms, which are taught in 이다 modifier 인 이었던 일. The next section covers what -(으)ㅁ cannot do.

What Can -(으)ㅁ Not Do?

The -(으)ㅁ ending cannot turn every verb into a normal noun, it is not natural in conversation, and it does not carry politeness. These limits explain most uses and errors.

• Not every verb has a dictionary noun. 웃음 and 꿈 are words, but 먹음 is not a word for "meal". Use 음식 or 식사 for that. The ending works productively only in note style.
• Not for conversation. 영화를 봤음을 알아요 sounds like a legal document. In speech, say 영화를 본 것을 알아요.
• No politeness. A line that ends on ㅁ is neutral and plain. To be polite, switch to a polite sentence ending.

What this lesson does not cover. It does not cover the full list of connecting patterns built on -(으)ㅁ, such as -(으)ㅁ에도 불구하고, which belong to advanced writing.

An honest limit. Which -(으)ㅁ nouns are real words must be checked in a dictionary. A form that follows the rule is not always a word that people use.

The next section collects the errors that appear most often.

What Mistakes Do Learners Make with -(으)ㅁ?

Learners make six predictable mistakes with -(으)ㅁ. Each one has a reason and a fix.

Learners often drop the ㄹ of an ㄹ-stem. Actually the ㄹ stays. Wrong: 사음 or 살음. Right: 삶. Fix: write ㄹ + ㅁ as one final cluster.

Learners often copy the ㅂ of a ㅂ-irregular stem. Actually ㅂ turns into 우. Wrong: 어렵음. Right: 어려움. Fix: build the polite form first; if the stem changes there, it changes here.

Learners often add 음 after a vowel. Actually a vowel stem takes ㅁ only. Wrong: 기쁘음. Right: 기쁨. Fix: a vowel stem takes the single consonant ㅁ.

Learners often invent nouns. Actually only dictionary words work as ordinary nouns. Wrong: 먹음 for "a meal". Right: 식사 or 음식. Fix: look the noun up before you use it in a normal sentence.

Learners often use -(으)ㅁ in speech. Actually conversation prefers -기 or -는 것. Wrong: 어제 갔음을 알았어요 in a chat. Right: 어제 간 것을 알았어요. Fix: save ㅁ for notes and formal text.

Learners often mix up 걸음 and 걷기. Actually 걸음 is a step or pace and 걷기 is the activity. Wrong: 걸음은 건강에 좋아요 for "Walking is good for health". Right: 걷기는 건강에 좋아요. Fix: ask whether you mean one step or the activity.

Practice turns these rules into habits, as the next section shows.

Practice and Answers

Complete the four tasks, then compare your answers with the key.

Task 1: choose the form. Write the -(으)ㅁ noun of each word.

1. 기쁘다 (be glad)
2. 웃다 (laugh)
3. 살다 (live)
4. 어렵다 (be hard)

Task 2: fix the error. Each word has one mistake. Rewrite it correctly.

1. 살음
2. 어렵음
3. 기쁘음

Task 3: translate into note style. Write in Korean: "Homework checked." and "Not applicable."

Task 4: write your own. Write one note-style line about today, for example 오늘 한국어를 공부함.

Answer key

1. (1) 기쁨 (2) 웃음 (3) 삶 (4) 어려움.
2. (1) 삶 (2) 어려움 (3) 기쁨.
3. 숙제를 확인함. 해당 없음.
4. Sample answers: 오늘 한국어를 공부함. 친구를 만남. Any note that ends on a verb plus ㅁ or 음 is correct.

If task 1 was correct, you have the formation rule. If task 2 was hard, return to the section on forming -(으)ㅁ. The next section points you to the lessons that follow.

Next Lessons after the -(으)ㅁ Nominalizer

After the -(으)ㅁ nominalizer, learn the everyday noun for facts in -는 것 nominalizer. Then read -기 vs -는 것 vs -(으)ㅁ to see all three together.

The wider set is listed on the parent page, Korean nominalization. Nouns that need a modifier in front of them are explained in Korean dependent nouns 것 수 때 줄 적.

This lesson covers the form and its four main settings. It does not cover advanced connecting patterns. About this page. Last updated 2026-10-09. The Korean text and spoken forms on this page were generated with AI assistance. Romanization follows the Revised Romanization of Korean and is shown only as a learning aid.

Frequently Asked Questions

What does the -(으)ㅁ nominalizer mean? The -(으)ㅁ nominalizer is an ending that turns a verb or an adjective into a noun for a result, a state or a feeling. 기쁘다 becomes 기쁨 ("joy"), and 웃다 becomes 웃음 ("laughter"). It is common in written notes and forms, and many results, such as 꿈 and 잠, are now ordinary words.

How do I form -(으)ㅁ? Add ㅁ to a stem that ends in a vowel and 음 to a stem that ends in a consonant. 기쁘다 gives 기쁨, and 웃다 gives 웃음. A stem that ends in ㄹ keeps the ㄹ, so 살다 gives 삶. Irregular stems change first: 어렵다 gives 어려움, and 걷다 gives 걸음.

What is the most common mistake with -(으)ㅁ? The most common mistake is forming the noun without applying the stem rules. Learners write 어렵음 for 어려움, 살음 for 삶, and 기쁘음 for 기쁨. The second mistake is using ㅁ in conversation, where -기 or -는 것 is natural. The third is inventing nouns that are not in the dictionary.

How is -(으)ㅁ different from -기 and -는 것? The -(으)ㅁ noun belongs to writing and gives a result or state, as in 숙제를 확인함. The -기 noun names an activity or plan, as in 확인하기 쉬워요. The -는 것 form names a fact or thing, as in 확인하는 것이 중요해요. In speech, -기 and -는 것 replace -(으)ㅁ.

Do I use -(으)ㅁ in speech, writing or both? Mainly in writing. Notes, forms, labels, book covers and formal reports use it, as in 해당 없음 and 홍길동 지음. A few nouns, such as 꿈, 잠 and 웃음, are normal speech. In conversation, a verb turned into a noun with -(으)ㅁ would sound stiff, so use -기 or -는 것.

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