Verbseoul.
하다 verb (adj)
강퍅하다gangpyakhadato be headstrong

To say to be headstrong politely in the present tense, use 강퍅해요 (gahng-pyah-kae-yoh). Below is the full conjugation of 강퍅하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
강퍅해
gahng-pyah-kae
강퍅해요
gahng-pyah-kae-yoh
강퍅합니다
gahng-pyah-kahm-nee-dah
Past
강퍅했어
gahng-pyah-kae-ssuh
강퍅했어요
gahng-pyah-kae-ssuh-yoh
강퍅했습니다
gahng-pyah-kae-sseum-nee-dah
Future
강퍅할 거야
gahng-pyah-kahl- -guh-yah
강퍅할 거예요
gahng-pyah-kahl- -guh-yae-yoh
강퍅할 겁니다
gahng-pyah-kahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
강퍅하세요
gahng-pyah-kah-sae-yoh
Suggestion / Let's Polite (요)
강퍅해요
gahng-pyah-kae-yoh
Question Polite (요)
강퍅해요?
gahng-pyah-kae-yoh-?
Connective “and” — (고)
강퍅하고
gahng-pyah-kah-goh
Conditional “if” — (면)
강퍅하면
gahng-pyah-kah-myuhn
Noun form — (기)
강퍅함
gahng-pyah-kahm