Verbseoul.
하다 verb
결정하다gyeoljeonghadato decide something, to make a decision

To say to decide something, to make a decision politely in the present tense, use 결정해요 (gyuhl-chuhng-hae-yoh). Below is the full conjugation of 결정하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
결정해
gyuhl-chuhng-hae
결정해요
gyuhl-chuhng-hae-yoh
결정합니다
gyuhl-chuhng-hahm-nee-dah
Past
결정했어
gyuhl-chuhng-hae-ssuh
결정했어요
gyuhl-chuhng-hae-ssuh-yoh
결정했습니다
gyuhl-chuhng-hae-sseum-nee-dah
Future
결정할 거야
gyuhl-chuhng-hahl- -guh-yah
결정할 거예요
gyuhl-chuhng-hahl- -guh-yae-yoh
결정할 겁니다
gyuhl-chuhng-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
결정하세요
gyuhl-chuhng-hah-sae-yoh
Suggestion / Let's Polite (요)
결정해요
gyuhl-chuhng-hae-yoh
Question Polite (요)
결정해요?
gyuhl-chuhng-hae-yoh-?
Connective “and” — (고)
결정하고
gyuhl-chuhng-hah-goh
Conditional “if” — (면)
결정하면
gyuhl-chuhng-hah-myuhn
Noun form — (기)
결정함
gyuhl-chuhng-hahm