Korean learners often struggle with the difference between ‘-(으)ㅁ’ and ‘-기’ when nominalizing verbs. While both turn verbs into nouns, they are used in different contexts. ‘-(으)ㅁ’ is common in formal writing and reports, whereas ‘-기’ is often used in spoken language and lists. This guide will explain their meanings, structures, and usage with clear examples.
Contents
1. Definition
Both ‘-(으)ㅁ’ and ‘-기’ are nominalization suffixes that transform verbs or adjectives into nouns. However, their usage differs based on context and formality:
- -(으)ㅁ: Commonly used in formal writing, such as reports, diaries, notices, or signs. It often conveys abstract ideas or states.
- -기: Frequently used in spoken Korean and informal contexts, such as expressing hobbies, preferences, or actions.
In English, these suffixes can be loosely compared to “-ing” (e.g., “reading”) or “-tion” (e.g., “completion”), depending on the context.
2. Form (Structure)
- -(으)ㅁ
- Attach ‘-음’ to verb/adjective stems ending in a consonant.
- Attach ‘-ㅁ’ to verb/adjective stems ending in a vowel.
- Primarily used in written language for formal or abstract expressions.
- -기
- Simply attach ‘-기’ to the verb/adjective stem, regardless of whether it ends in a consonant or vowel.
- Commonly used in spoken language for describing actions, hobbies, or making lists.
| Verb/Adjective | -(으)ㅁ Form | –기 Form | Usage Example |
| 먹다 (to eat) | 먹음 | 먹기 | 보고서: 음식 섭취를 기록함 (Report: Recording food intake) 취미: 먹기 좋아해요 (Hobby: I like eating) |
| 가다 (to go) | 감 | 가기 | 표지판: 출입 금지함 (Sign: Entry prohibited) 일상: 여행 가기 (Daily life: Going on a trip) |
| 읽다 (to read) | 읽음 | 읽기 | 일기: 오늘 책 읽음을 정리함 (Diary: Summarizing today’s book reading) 취미: 책 읽기 좋아요 (Hobby: I like reading books) |
| 좋다 (to be good) | 좋음 | 좋기 | 보고서: 결과가 좋음을 확인함 (Report: Confirming that the results are good) 일상: 날씨가 좋기를 바라요 (Daily life: I hope the weather will be good) |
3. Meaning & Usage
- Formal vs. Informal Usage
- ‘-(으)ㅁ’ is used in formal and written contexts, while ‘-기’ is more common in everyday speech.
- Examples:
- 연구 결과를 분석함. (Analyzing research results.) ✅
- 연구 결과를 분석하기. (Less common in formal writing.) ❌
- 나는 영화 보기 좋아해. (I like watching movies.) ✅
- 나는 영화 봄을 좋아해. (Unnatural in spoken Korean.) ❌
2. Summarization vs. Action Focus
- ‘-(으)ㅁ’ is often used for summarization and reporting.
- ‘-기’ is used for describing ongoing actions or preferences.
- Examples:
- 출입 금지함. (No entry.) ✅
- 출입 금지하기. (Unnatural for signs.) ❌
- 나는 운동하기를 목표로 삼았다. (I set a goal to exercise.) ✅
- 나는 운동함을 목표로 삼았다. (Unnatural.) ❌
3. Common Usage in Signs & Notices
- ‘-(으)ㅁ’ is frequently found in official documents, notices, and signs to convey rules or prohibitions.
- ‘-기’ is less commonly used in such contexts.
Examples:
- 주차 금지함. (No parking.) ✅
- 주차 금지하기. (Unnatural.) ❌
- 음식물 반입 금지함. (No outside food allowed.) ✅
- 음식물 반입 금지하기. (Unnatural.) ❌
4. Expressing Hopes, Desires, and Preferences
- ‘-기’ is often used when talking about hopes, plans, or habits because it focuses on actions or processes.
Examples:
- 내년에는 한국어 배우기를 계획하고 있다. (I plan to learn Korean next year.) ✅
- 내년에는 한국어 배움을 계획하고 있다. (Less natural.) ❌
- 건강을 위해 매일 운동하기로 했다. (I decided to exercise every day.) ✅
- 건강을 위해 매일 운동함으로 했다. (Unnatural.) ❌
5. Some Words Favor One Form Over the Other
Certain words naturally pair with either ‘-(으)ㅁ’ or ‘-기’. While both forms can sometimes be grammatically correct, one form may sound more natural depending on common usage.
| Verb | -(으)ㅁ | -기 |
| 기억하다 (to remember) | 기억함 ❌ | 기억하기 ✅ |
| 인정하다 (to acknowledge) | 인정함 ✅ | 인정하기 ✅ (less common) |
| 준비하다 (to prepare) | 준비함 ❌ | 준비하기 ✅ |
| 확인하다 (to confirm) | 확인함 ✅ | 확인하기 ✅ (less common) |
| 사랑하다 (to love) | 사랑함 ✅ (used in literary contexts) | 사랑하기 ✅ (used in daily speech) |
📌 Note: Both forms of “인정하다” and “확인하다” can be used, but the -(으)ㅁ form is more common in formal writing.
4. Key Points to Remember
- -(으)ㅁ is more formal and abstract; it’s often found in written contexts like reports, diaries, and signs.
- -기 is more casual and action-oriented; it’s commonly used in spoken language to describe activities or preferences.
- Some words naturally prefer one form over the other depending on common usage.
5. Practice Exercises
Fill in the blanks with the correct form (-음/-ㅁ or -기):
- ______ 전에 손을 씻으세요.
(Wash your hands before eating.) - 내 취미는 ______이다.
(My hobby is listening to music.) - 출입 ______!
(No entry!) - 나는 요즘 ______를 배우는 중이야.
(I am learning to cook these days.) - 보고서 작성 시 ______가 중요하다.
(Organizing content is important when writing reports.) - 그는 매일 ______를 목표로 삼았다.
(He set a goal to exercise every day.) - 오늘의 날씨가 ______을 알 수 있다.
(You can tell that today’s weather is good.) - 한국어를 ______는 어렵지만 재미있어요.
(It is hard but fun to study Korean.) - 이 문제를 ______가 필요합니다!
(Solving this problem is necessary!) - 그녀는 ______를 즐겨요!
(She enjoys drawing pictures!)
6. Answers
- 먹기
- 음악 듣기
- 금지함
- 요리하기
- 정리하기
- 운동하기
- 좋음
- 공부하기
- 해결하기
- 그림 그리기
7. Common Mistakes and Tips
⚠️ Mistake 1: Using -(으)ㅁ with action verbs in casual speech
Incorrect: 나는 운동 함을 좋아해요. ❌ (I like exercising.)
Correct: 나는 운동하기를 좋아해요. ✅ (I like exercising.)
💡 Tip: Use -기 for hobbies, lists, or general actions in daily conversations. Action verbs are more naturally nominalized with “-기” in casual contexts.
⚠️ Mistake 2: Using -기 for abstract qualities
Incorrect: 그의 친절하기가 인상적이었어요. ❌ (His kindness was impressive.)
Correct: 그의 친절함이 인상적이었어요. ✅ (His kindness was impressive.)
💡 Tip: Use -(으)ㅁ for formal writing or abstract ideas like qualities and states. Abstract concepts are better expressed with “-(으)ㅁ” to emphasize their noun-like quality.
⚠️ Mistake 3: Forgetting particles after nominalized forms
Incorrect: 한국어 배우기 어려워요. ❌ (Learning Korean is difficult.)
Correct: 한국어 배우기가 어려워요. ✅ (Learning Korean is difficult.)
💡 Tip: Always include particles (e.g., -가, -를, -는) after nominalized forms to ensure grammatical accuracy and clarity.
Understanding the differences between ‘-(으)ㅁ’ and ‘-기’ can help you use them correctly in different contexts. Practice using both forms in writing and speaking to get comfortable with their distinctions!