Verbseoul.
하다 verb
결심하다gyeolsimhadato be determined to, to resolve to

To say to be determined to, to resolve to politely in the present tense, use 결심해요 (gyuhl-sheem-hae-yoh). Below is the full conjugation of 결심하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
결심해
gyuhl-sheem-hae
결심해요
gyuhl-sheem-hae-yoh
결심합니다
gyuhl-sheem-hahm-nee-dah
Past
결심했어
gyuhl-sheem-hae-ssuh
결심했어요
gyuhl-sheem-hae-ssuh-yoh
결심했습니다
gyuhl-sheem-hae-sseum-nee-dah
Future
결심할 거야
gyuhl-sheem-hahl- -guh-yah
결심할 거예요
gyuhl-sheem-hahl- -guh-yae-yoh
결심할 겁니다
gyuhl-sheem-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
결심하세요
gyuhl-sheem-hah-sae-yoh
Suggestion / Let's Polite (요)
결심해요
gyuhl-sheem-hae-yoh
Question Polite (요)
결심해요?
gyuhl-sheem-hae-yoh-?
Connective “and” — (고)
결심하고
gyuhl-sheem-hah-goh
Conditional “if” — (면)
결심하면
gyuhl-sheem-hah-myuhn
Noun form — (기)
결심함
gyuhl-sheem-hahm