Verbseoul.
ㄹ stem
말다maldato not do something, to stop doing

To say to not do something, to stop doing politely in the present tense, use 말아요 (mah-rah-yoh). Below is the full conjugation of 말다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
말아
mah-rah
말아요
mah-rah-yoh
맙니다
mahm-nee-dah
Past
말았어
mah-rah-ssuh
말았어요
mah-rah-ssuh-yoh
말았습니다
mah-rah-sseum-nee-dah
Future
말 거야
mahl- -guh-yah
말 거예요
mahl- -guh-yae-yoh
말 겁니다
mahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
마세요
mah-sae-yoh
Suggestion / Let's Polite (요)
말아요
mah-rah-yoh
Question Polite (요)
말아요?
mah-rah-yoh-?
Connective “and” — (고)
말고
mahl-goh
Conditional “if” — (면)
말면
mahl-myuhn
Noun form — (기)
mahm