Verbseoul.
하다 verb
구입하다guiphadato purchase, to buy

To say to purchase, to buy politely in the present tense, use 구입해요 (goo-ee-pae-yoh). Below is the full conjugation of 구입하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
구입해
goo-ee-pae
구입해요
goo-ee-pae-yoh
구입합니다
goo-ee-pahm-nee-dah
Past
구입했어
goo-ee-pae-ssuh
구입했어요
goo-ee-pae-ssuh-yoh
구입했습니다
goo-ee-pae-sseum-nee-dah
Future
구입할 거야
goo-ee-pahl- -guh-yah
구입할 거예요
goo-ee-pahl- -guh-yae-yoh
구입할 겁니다
goo-ee-pahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
구입하세요
goo-ee-pah-sae-yoh
Suggestion / Let's Polite (요)
구입해요
goo-ee-pae-yoh
Question Polite (요)
구입해요?
goo-ee-pae-yoh-?
Connective “and” — (고)
구입하고
goo-ee-pah-goh
Conditional “if” — (면)
구입하면
goo-ee-pah-myuhn
Noun form — (기)
구입함
goo-ee-pahm