Verbseoul.
하다 verb
발생하다balsaenghadato occur, to happen

To say to occur, to happen politely in the present tense, use 발생해요 (bahl-saeng-hae-yoh). Below is the full conjugation of 발생하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
발생해
bahl-saeng-hae
발생해요
bahl-saeng-hae-yoh
발생합니다
bahl-saeng-hahm-nee-dah
Past
발생했어
bahl-saeng-hae-ssuh
발생했어요
bahl-saeng-hae-ssuh-yoh
발생했습니다
bahl-saeng-hae-sseum-nee-dah
Future
발생할 거야
bahl-saeng-hahl- -guh-yah
발생할 거예요
bahl-saeng-hahl- -guh-yae-yoh
발생할 겁니다
bahl-saeng-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
발생하세요
bahl-saeng-hah-sae-yoh
Suggestion / Let's Polite (요)
발생해요
bahl-saeng-hae-yoh
Question Polite (요)
발생해요?
bahl-saeng-hae-yoh-?
Connective “and” — (고)
발생하고
bahl-saeng-hah-goh
Conditional “if” — (면)
발생하면
bahl-saeng-hah-myuhn
Noun form — (기)
발생함
bahl-saeng-hahm