Core Pattern Rule: It is natural that... (-는 법이다)
The pattern -는 법이다 is used to state that something is a universal truth, a natural law, or an inevitable outcome. It's like saying "it's the way of things," "it's bound to happen," or "it's a rule that...". It's frequently used in proverbs and when giving life advice.
Formation
This pattern attaches differently depending on the word type.
Action Verbs: Add -는 법이다 to the verb stem.
가다 → 가는 법이다 (is bound to go)
거두다 → 거두는 법이다 (is bound to reap)
Descriptive Verbs (Adjectives): Add -(으)ㄴ 법이다.
Vowel stem: -(ㄴ) 법이다 (e.g., 예쁘다 → 예쁜 법이다)
Consonant stem: -(은) 법이다 (e.g., 좋다 → 좋은 법이다)
Nouns: Add -인 법이다.
약 → 약인 법이다 (is bound to be medicine)
있다 / 없다: Use -는 법이다.
있다 → 있는 법이다 (is bound to exist)
뿌린 대로 거두는 법이야. / 사랑은 변하는 법이야. / 시간이 약인 법이야. / 다 때가 있는 법이야.
Synonyms & Differences: -는 법이다 vs. -기 마련이다
-는 법이다 is very similar to another pattern, -기 마련이다. Both express that something is natural or inevitable, and they are often interchangeable.
Key Distinction
-는 법이다: Literally means "it is the law/rule that...". It emphasizes a universal principle, a moral law, or a rule of nature. It often sounds more definitive and is common in established proverbs.
진실은 승리하는 법이다. (It's a rule that truth wins.)
-기 마련이다: Literally means "it is prepared/arranged that...". It focuses more on a natural tendency or an expected outcome in a given situation. It can feel slightly softer, like an observation of what usually happens.
오래 쓰면 고장 나기 마련이다. (If you use it for a long time, it's natural that it breaks down.)
Interchangeability
In many contexts, the nuance is subtle, and you can use either one. Both of the following sentences are perfectly natural.
비밀은 밝혀지는 법이다. (Secrets are bound to be revealed.)