Verbseoul.
하다 verb (adj)
완고하다wangohadastubborn

To say stubborn politely in the present tense, use 완고해요 (wahn-goh-hae-yoh). Below is the full conjugation of 완고하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
완고해
wahn-goh-hae
완고해요
wahn-goh-hae-yoh
완고합니다
wahn-goh-hahm-nee-dah
Past
완고했어
wahn-goh-hae-ssuh
완고했어요
wahn-goh-hae-ssuh-yoh
완고했습니다
wahn-goh-hae-sseum-nee-dah
Future
완고할 거야
wahn-goh-hahl- -guh-yah
완고할 거예요
wahn-goh-hahl- -guh-yae-yoh
완고할 겁니다
wahn-goh-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
완고하세요
wahn-goh-hah-sae-yoh
Suggestion / Let's Polite (요)
완고해요
wahn-goh-hae-yoh
Question Polite (요)
완고해요?
wahn-goh-hae-yoh-?
Connective “and” — (고)
완고하고
wahn-goh-hah-goh
Conditional “if” — (면)
완고하면
wahn-goh-hah-myuhn
Noun form — (기)
완고함
wahn-goh-hahm