Let's learn how to use the V/A+기 마련이다 Korean Grammar with some simple and easy-to-understand example sentences.
V/A+기 마련이다 - “It is natural that… / It’s inevitable that… / It’s bound to…”
USE:
“It is natural that… / It’s inevitable that… / It’s bound to…”
Used to express something that normally, naturally, or inevitably happens.
Often used for general truths, human nature, or expected outcomes.
It shows that the situation is normal and not surprising.
CONJUGATION RULE
Attach -기 마련이다 to the verb stem or adjective stem:
Verb/Adjective → -기 마련이다
실수하다 → 실수하기 마련이다 (It’s natural to make mistakes)
시간이 걸리다 → 시간이 걸리기 마련이다 (It inevitably takes time)
Past forms can also be used when describing a general truth from past experience:
했기 마련이다
생기기 마련이었다
The ending can change:
-기 마련이에요 (polite)
-기 마련이죠 (soft, conversational)
-기 마련입니다 (formal)
EXAMPLE SENTENCES:
1. 사람은 누구나 실수하기 마련이에요.
→ Everyone is bound to make mistakes.
2. 처음 배우면 어려운 법이기 마련이에요.
→ When you first learn something, it’s naturally difficult.
3. 날씨가 추우면 감기 걸리기 마련이죠.
→ When the weather is cold, catching a cold is natural.
4. 노력하면 결과가 나오기 마련입니다.
→ If you put in effort, results are bound to come.
5. 시간이 지나면 상처도 잊히기 마련이에요.
→ With time, wounds (emotional ones) are bound to fade.
6. 아이들은 금방 자라기 마련이에요.
→ Children are bound to grow quickly.
Additional Notes
Expresses general truths or patterns in life.
Sounds a bit philosophical or wise, like natural human behavior or life lessons.
Similar expressions:
-게 마련이다 → same meaning, just more natural with adjectives
당연하다 → means “natural,” but not used in the same grammar position
Difference:
-기 마련이다 = more about things that naturally happen
-게 마련이다 = more about a result or way something happens

