The most common Korean word for “suddenly” is 갑자기 (gapjagi). 「suddenly」는 한국어로 갑자기.
Learn 갑자기 free — flashcards, audio and review →「갑자기」 단어장으로 무료로 외우기Words and levels: TOPIK I essentials (National Institute of Korean Language standard curriculum, KOGL Type 1) · examples: Cheesepotato