Verbseoul.
하다 verb (adj)
확고하다hwakgohadato be firm, to be staunch, to be adamant

To say to be firm, to be staunch, to be adamant politely in the present tense, use 확고해요 (hwahg-ggoh-hae-yoh). Below is the full conjugation of 확고하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
확고해
hwahg-ggoh-hae
확고해요
hwahg-ggoh-hae-yoh
확고합니다
hwahg-ggoh-hahm-nee-dah
Past
확고했어
hwahg-ggoh-hae-ssuh
확고했어요
hwahg-ggoh-hae-ssuh-yoh
확고했습니다
hwahg-ggoh-hae-sseum-nee-dah
Future
확고할 거야
hwahg-ggoh-hahl- -guh-yah
확고할 거예요
hwahg-ggoh-hahl- -guh-yae-yoh
확고할 겁니다
hwahg-ggoh-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
확고하세요
hwahg-ggoh-hah-sae-yoh
Suggestion / Let's Polite (요)
확고해요
hwahg-ggoh-hae-yoh
Question Polite (요)
확고해요?
hwahg-ggoh-hae-yoh-?
Connective “and” — (고)
확고하고
hwahg-ggoh-hah-goh
Conditional “if” — (면)
확고하면
hwahg-ggoh-hah-myuhn
Noun form — (기)
확고함
hwahg-ggoh-hahm