Verbseoul.
하다 verb
개시하다gaesihadato start

To say to start politely in the present tense, use 개시해요 (gae-shee-hae-yoh). Below is the full conjugation of 개시하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
개시해
gae-shee-hae
개시해요
gae-shee-hae-yoh
개시합니다
gae-shee-hahm-nee-dah
Past
개시했어
gae-shee-hae-ssuh
개시했어요
gae-shee-hae-ssuh-yoh
개시했습니다
gae-shee-hae-sseum-nee-dah
Future
개시할 거야
gae-shee-hahl- -guh-yah
개시할 거예요
gae-shee-hahl- -guh-yae-yoh
개시할 겁니다
gae-shee-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
개시하세요
gae-shee-hah-sae-yoh
Suggestion / Let's Polite (요)
개시해요
gae-shee-hae-yoh
Question Polite (요)
개시해요?
gae-shee-hae-yoh-?
Connective “and” — (고)
개시하고
gae-shee-hah-goh
Conditional “if” — (면)
개시하면
gae-shee-hah-myuhn
Noun form — (기)
개시함
gae-shee-hahm