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