Verbseoul.
하다 verb
가하다gahadato add

To say to add politely in the present tense, use 가해요 (gah-hae-yoh). Below is the full conjugation of 가하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
가해
gah-hae
가해요
gah-hae-yoh
가합니다
gah-hahm-nee-dah
Past
가했어
gah-hae-ssuh
가했어요
gah-hae-ssuh-yoh
가했습니다
gah-hae-sseum-nee-dah
Future
가할 거야
gah-hahl- -guh-yah
가할 거예요
gah-hahl- -guh-yae-yoh
가할 겁니다
gah-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
가하세요
gah-hah-sae-yoh
Suggestion / Let's Polite (요)
가해요
gah-hae-yoh
Question Polite (요)
가해요?
gah-hae-yoh-?
Connective “and” — (고)
가하고
gah-hah-goh
Conditional “if” — (면)
가하면
gah-hah-myuhn
Noun form — (기)
가함
gah-hahm