Verbseoul.
하다 verb (adj)
무력하다muryeokhadapowerless, helpless, impotent

To say powerless, helpless, impotent politely in the present tense, use 무력해요 (moo-ryuh-kae-yoh). Below is the full conjugation of 무력하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
무력해
moo-ryuh-kae
무력해요
moo-ryuh-kae-yoh
무력합니다
moo-ryuh-kahm-nee-dah
Past
무력했어
moo-ryuh-kae-ssuh
무력했어요
moo-ryuh-kae-ssuh-yoh
무력했습니다
moo-ryuh-kae-sseum-nee-dah
Future
무력할 거야
moo-ryuh-kahl- -guh-yah
무력할 거예요
moo-ryuh-kahl- -guh-yae-yoh
무력할 겁니다
moo-ryuh-kahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
무력하세요
moo-ryuh-kah-sae-yoh
Suggestion / Let's Polite (요)
무력해요
moo-ryuh-kae-yoh
Question Polite (요)
무력해요?
moo-ryuh-kae-yoh-?
Connective “and” — (고)
무력하고
moo-ryuh-kah-goh
Conditional “if” — (면)
무력하면
moo-ryuh-kah-myuhn
Noun form — (기)
무력함
moo-ryuh-kahm