Verbseoul.
하다 verb (adj)
무책임하다muchaekimhadairresponsible

To say irresponsible politely in the present tense, use 무책임해요 (moo-chae-geem-hae-yoh). Below is the full conjugation of 무책임하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
무책임해
moo-chae-geem-hae
무책임해요
moo-chae-geem-hae-yoh
무책임합니다
moo-chae-geem-hahm-nee-dah
Past
무책임했어
moo-chae-geem-hae-ssuh
무책임했어요
moo-chae-geem-hae-ssuh-yoh
무책임했습니다
moo-chae-geem-hae-sseum-nee-dah
Future
무책임할 거야
moo-chae-geem-hahl- -guh-yah
무책임할 거예요
moo-chae-geem-hahl- -guh-yae-yoh
무책임할 겁니다
moo-chae-geem-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
무책임하세요
moo-chae-geem-hah-sae-yoh
Suggestion / Let's Polite (요)
무책임해요
moo-chae-geem-hae-yoh
Question Polite (요)
무책임해요?
moo-chae-geem-hae-yoh-?
Connective “and” — (고)
무책임하고
moo-chae-geem-hah-goh
Conditional “if” — (면)
무책임하면
moo-chae-geem-hah-myuhn
Noun form — (기)
무책임함
moo-chae-geem-hahm