Verbseoul.
descriptive
쎄다ssedacolloquial form of 세다 (seda, “to be strong”)

To say colloquial form of 세다 (seda, “to be strong”) politely in the present tense, use 쎄요 (ssae-yoh). Below is the full conjugation of 쎄다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
ssae
쎄요
ssae-yoh
쎕니다
ssaem-nee-dah
Past
쎘어
ssae-ssuh
쎘어요
ssae-ssuh-yoh
쎘습니다
ssae-sseum-nee-dah
Future
쎌 거야
ssael- -guh-yah
쎌 거예요
ssael- -guh-yae-yoh
쎌 겁니다
ssael- -guhm-nee-dah

Other useful forms

Command Polite (세요)
쎄세요
ssae-sae-yoh
Suggestion / Let's Polite (요)
쎄요
ssae-yoh
Question Polite (요)
쎄요?
ssae-yoh-?
Connective “and” — (고)
쎄고
ssae-goh
Conditional “if” — (면)
쎄면
ssae-myuhn
Noun form — (기)
ssaem