Verbseoul.
하다 verb
공지하다gongjihadato announce

To say to announce politely in the present tense, use 공지해요 (gohng-chee-hae-yoh). Below is the full conjugation of 공지하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
공지해
gohng-chee-hae
공지해요
gohng-chee-hae-yoh
공지합니다
gohng-chee-hahm-nee-dah
Past
공지했어
gohng-chee-hae-ssuh
공지했어요
gohng-chee-hae-ssuh-yoh
공지했습니다
gohng-chee-hae-sseum-nee-dah
Future
공지할 거야
gohng-chee-hahl- -guh-yah
공지할 거예요
gohng-chee-hahl- -guh-yae-yoh
공지할 겁니다
gohng-chee-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
공지하세요
gohng-chee-hah-sae-yoh
Suggestion / Let's Polite (요)
공지해요
gohng-chee-hae-yoh
Question Polite (요)
공지해요?
gohng-chee-hae-yoh-?
Connective “and” — (고)
공지하고
gohng-chee-hah-goh
Conditional “if” — (면)
공지하면
gohng-chee-hah-myuhn
Noun form — (기)
공지함
gohng-chee-hahm