Verbseoul.
하다 verb
계약하다gyeyakhadato contract

To say to contract politely in the present tense, use 계약해요 (gyae-yah-kae-yoh). Below is the full conjugation of 계약하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
계약해
gyae-yah-kae
계약해요
gyae-yah-kae-yoh
계약합니다
gyae-yah-kahm-nee-dah
Past
계약했어
gyae-yah-kae-ssuh
계약했어요
gyae-yah-kae-ssuh-yoh
계약했습니다
gyae-yah-kae-sseum-nee-dah
Future
계약할 거야
gyae-yah-kahl- -guh-yah
계약할 거예요
gyae-yah-kahl- -guh-yae-yoh
계약할 겁니다
gyae-yah-kahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
계약하세요
gyae-yah-kah-sae-yoh
Suggestion / Let's Polite (요)
계약해요
gyae-yah-kae-yoh
Question Polite (요)
계약해요?
gyae-yah-kae-yoh-?
Connective “and” — (고)
계약하고
gyae-yah-kah-goh
Conditional “if” — (면)
계약하면
gyae-yah-kah-myuhn
Noun form — (기)
계약함
gyae-yah-kahm