Core Pattern Rule: Using -기 for Promises and Lists
The -기 ending is a simple yet powerful tool for turning a verb into a noun phrase. In this pattern, it's used to end a sentence, creating a concise statement that functions like a promise, a resolution, a rule, or an item on a to-do list.
Meaning & Usage
Meaning: It nominalizes the verb, essentially turning "to do [verb]" into a standalone statement. Think of it as a label for an action.
When to use: Use it for making personal resolutions (like for the New Year), setting ground rules with someone, or writing down a list of tasks. It has a declarative, slightly impersonal tone.
Formation
It's very simple: just attach -기 directly to the verb stem, regardless of whether it ends in a vowel or a consonant.
하다 (to do): 하 + 기 → 하기
먹다 (to eat): 먹 + 기 → 먹기
않다 (to not do): 않 + 기 → 않기 (e.g., 지각하지 않기 - No being late)
지각하지 않기. / 밥 잘 챙겨 먹기. / 한국어 열심히 공부하기. / 포기하지 않기.
Native Nuance & Mistakes
While -기 is a sentence-ending form, it's not a typical conversational sentence. Understanding its specific function is key to using it naturally.
It's a Fragment, Not a Full Sentence
Think of -기 endings as bullet points or headlines. They state a topic or a rule without the grammatical structure of a full sentence like "I will..." or "You should...".
Correct: 방 청소하기. (As a to-do list item: "Clean room.")
Incorrect: 저는 방 청소하기. (To mean "I am cleaning my room." You should say 저는 방 청소해요.)
Context is Everything
This pattern is used in specific contexts like setting goals, making promises, or listing rules. It's not used for general narration or describing ongoing actions. You'll often see it on signs, in rulebooks, or hear it when people are making firm agreements.
Natural: (Making a New Year's resolution) 새해 목표: 돈 아껴 쓰기, 긍정적으로 생각하기.
Awkward: (Telling a friend what you did) 어제 친구랑 약속 지키기. (Should be: 어제 친구랑 약속 지켰어요.)