Verbseoul.
하다 verb
거절하다geojeolhadato refuse

To say to refuse politely in the present tense, use 거절해요 (guh-chuhl-hae-yoh). Below is the full conjugation of 거절하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
거절해
guh-chuhl-hae
거절해요
guh-chuhl-hae-yoh
거절합니다
guh-chuhl-hahm-nee-dah
Past
거절했어
guh-chuhl-hae-ssuh
거절했어요
guh-chuhl-hae-ssuh-yoh
거절했습니다
guh-chuhl-hae-sseum-nee-dah
Future
거절할 거야
guh-chuhl-hahl- -guh-yah
거절할 거예요
guh-chuhl-hahl- -guh-yae-yoh
거절할 겁니다
guh-chuhl-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
거절하세요
guh-chuhl-hah-sae-yoh
Suggestion / Let's Polite (요)
거절해요
guh-chuhl-hae-yoh
Question Polite (요)
거절해요?
guh-chuhl-hae-yoh-?
Connective “and” — (고)
거절하고
guh-chuhl-hah-goh
Conditional “if” — (면)
거절하면
guh-chuhl-hah-myuhn
Noun form — (기)
거절함
guh-chuhl-hahm