Verbseoul.
descriptive
못되다motdoedanasty, mean, evil

To say nasty, mean, evil politely in the present tense, use 못돼요 (moh-ttwae-yoh). Below is the full conjugation of 못되다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
못돼
moh-ttwae
못돼요
moh-ttwae-yoh
못됩니다
moh-ttwaem-nee-dah
Past
못됐어
moh-ttwae-ssuh
못됐어요
moh-ttwae-ssuh-yoh
못됐습니다
moh-ttwae-sseum-nee-dah
Future
못될 거야
moh-ttwael- -guh-yah
못될 거예요
moh-ttwael- -guh-yae-yoh
못될 겁니다
moh-ttwael- -guhm-nee-dah

Other useful forms

Command Polite (세요)
못되세요
moh-ttwae-sae-yoh
Suggestion / Let's Polite (요)
못돼요
moh-ttwae-yoh
Question Polite (요)
못돼요?
moh-ttwae-yoh-?
Connective “and” — (고)
못되고
moh-ttwae-goh
Conditional “if” — (면)
못되면
moh-ttwae-myuhn
Noun form — (기)
못됨
moh-ttwaem