Verbseoul.
하다 verb
개척하다gaecheokhadato reclaim, to cultivate, to develop

To say to reclaim, to cultivate, to develop politely in the present tense, use 개척해요 (gae-chuh-kae-yoh). Below is the full conjugation of 개척하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
개척해
gae-chuh-kae
개척해요
gae-chuh-kae-yoh
개척합니다
gae-chuh-kahm-nee-dah
Past
개척했어
gae-chuh-kae-ssuh
개척했어요
gae-chuh-kae-ssuh-yoh
개척했습니다
gae-chuh-kae-sseum-nee-dah
Future
개척할 거야
gae-chuh-kahl- -guh-yah
개척할 거예요
gae-chuh-kahl- -guh-yae-yoh
개척할 겁니다
gae-chuh-kahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
개척하세요
gae-chuh-kah-sae-yoh
Suggestion / Let's Polite (요)
개척해요
gae-chuh-kae-yoh
Question Polite (요)
개척해요?
gae-chuh-kae-yoh-?
Connective “and” — (고)
개척하고
gae-chuh-kah-goh
Conditional “if” — (면)
개척하면
gae-chuh-kah-myuhn
Noun form — (기)
개척함
gae-chuh-kahm