This is the 13402nd most frequent Korean word.
떄문이다
"떄문이다" means "because" or "due to."
The word '때문이다' is used here to explain the reason behind failing the test, linking the lack of study as the cause.
시험에 미끄러진 이유는 충분히 공부하지 않았기 때문이다.
The reason I failed the test is because I didn't study enough.
In this sentence, '때문이다' identifies the reason for the success, highlighting continuous effort.
그 성취는 그의 끊임없는 노력 때문이었다.
The achievement was due to his relentless efforts.
Here, '때문이다' explains the cause of the participation in the festival, relating it to the local holiday.