Verbseoul.
하다 verb (adj)
유효하다yuhyohadaeffective, valid

To say effective, valid politely in the present tense, use 유효해요 (yoo-hyoh-hae-yoh). Below is the full conjugation of 유효하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
유효해
yoo-hyoh-hae
유효해요
yoo-hyoh-hae-yoh
유효합니다
yoo-hyoh-hahm-nee-dah
Past
유효했어
yoo-hyoh-hae-ssuh
유효했어요
yoo-hyoh-hae-ssuh-yoh
유효했습니다
yoo-hyoh-hae-sseum-nee-dah
Future
유효할 거야
yoo-hyoh-hahl- -guh-yah
유효할 거예요
yoo-hyoh-hahl- -guh-yae-yoh
유효할 겁니다
yoo-hyoh-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
유효하세요
yoo-hyoh-hah-sae-yoh
Suggestion / Let's Polite (요)
유효해요
yoo-hyoh-hae-yoh
Question Polite (요)
유효해요?
yoo-hyoh-hae-yoh-?
Connective “and” — (고)
유효하고
yoo-hyoh-hah-goh
Conditional “if” — (면)
유효하면
yoo-hyoh-hah-myuhn
Noun form — (기)
유효함
yoo-hyoh-hahm