Grammar
-(으)ㄴ 것은 -이다
Meaning
Advanced-(eu)n geoseun -ida
A cleft-sentence pattern that turns a clause into a noun phrase with -(으)ㄴ 것 ('the thing that ~'), marks it as the topic with 은/는, and completes it with -이다. It works like English 'What ~ is ...' or 'It is ... that ~,' and is often used in news or formal writing to spotlight a specific fact.
Form
Attach -(으)ㄴ (ㄴ after a vowel-final stem, 은 after a consonant-final stem) to a verb stem, then add 것은, followed by the emphasized information + 이다: 손상되다 → 손상된 것은 ... 이다. Because -(으)ㄴ is the past/completed modifier, this pattern almost always points to something that has already happened. -이다 itself conjugates for tense and formality at the end (이다/였다/입니다 등).
Examples
손상된 엔진을 공개한 것은 이번이 처음이다.
This is the first time a damaged engine has been made public.
그가 사과한 것은 이번이 처음이다.
This is the first time he apologized.
우리가 확인한 것은 사실이 아니었다.
What we confirmed turned out not to be true.
Common mistakes & nuance
This is mainly a written/formal pattern (news, essays, reports) rather than everyday conversation. Because 것 nominalizes the whole preceding clause, make sure the clause before 것은 is a complete idea, not just a noun.
Similar grammar
- -기 때문이다
-기 때문이다 gives a reason for something ('it is because ~'). -(으)ㄴ 것은 -이다 does not explain a cause — it identifies or spotlights which fact is true, similar to an English cleft sentence.