Verbseoul.
르 irregular (adj)
가파르다gapareudato be steep (of a road, path, or slope)

To say to be steep (of a road, path, or slope) politely in the present tense, use 가팔라요 (gah-pahl-rah-yoh). Below is the full conjugation of 가파르다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
가팔라
gah-pahl-rah
가팔라요
gah-pahl-rah-yoh
가파릅니다
gah-pah-reum-nee-dah
Past
가팔랐어
gah-pahl-rah-ssuh
가팔랐어요
gah-pahl-rah-ssuh-yoh
가팔랐습니다
gah-pahl-rah-sseum-nee-dah
Future
가파를 거야
gah-pah-reul- -guh-yah
가파를 거예요
gah-pah-reul- -guh-yae-yoh
가파를 겁니다
gah-pah-reul- -guhm-nee-dah

Other useful forms

Command Polite (세요)
가파르세요
gah-pah-reu-sae-yoh
Suggestion / Let's Polite (요)
가팔라요
gah-pahl-rah-yoh
Question Polite (요)
가팔라요?
gah-pahl-rah-yoh-?
Connective “and” — (고)
가파르고
gah-pah-reu-goh
Conditional “if” — (면)
가파르면
gah-pah-reu-myuhn
Noun form — (기)
가파름
gah-pah-reum