Textbook vs Real
Textbook첫 번째 눈이 내리고 있습니다cheot beon-jjae nun-i nae-ri-go it-seum-ni-da
Real첫눈이 온다cheot-nun-i on-da
Why Koreans say it this way
Kim Shin's iconic line. Uses the poetic plain form (~다) instead of formal speech. 첫눈 is a compound word (first + snow) — textbooks would break it apart. In Korean culture, watching first snow together means your love will last.
From: 도깨비 EP1