Verbseoul.
ㄹ stem

까불다 conjugation (kkabulda, to act up, to fool around)

To say to act up, to fool around politely in the present tense, use 까불어요 (ggah-boo-ruh-yoh) · kkabureoyo. Below is the full conjugation of 까불다 across the three tenses and three everyday speech levels.

Grammar note (ㄹ stem): ㄹ-stem verbs end in ㄹ as the final consonant. They are conjugated regularly with vowel suffixes (살다 → 살아요), but the ㄹ drops before certain consonant suffixes — specifically before ㄴ, ㅂ, ㅅ, and before the formal ending 습니다: 살다 → 사는, 삽니다, 살지 (ㄹ kept before ㅈ). This is sometimes called a "ㄹ drop" or "ㄹ irregular." See all ㄹ-stem verbs →

Conjugation table

pron. = pronunciation guide  · RR = Revised Romanization

Highlighted = where the stem changes

TenseCasual (반말)Polite (요)Formal (합니다)
Present
까불어
ggah-boo-ruh
kkabureo
까불어요
ggah-boo-ruh-yoh
kkabureoyo
까붑니다
ggah-boom-nee-dah
kkabumnida
Past
까불었어
ggah-boo-ruh-ssuh
kkabureosseo
까불었어요
ggah-boo-ruh-ssuh-yoh
kkabureosseoyo
까불었습니다
ggah-boo-ruh-sseum-nee-dah
kkabureosseumnida
Future
까불 거야
ggah-bool guh-yah
kkabul geoya
까불 거예요
ggah-bool guh-yae-yoh
kkabul geoyeyo
까불 겁니다
ggah-bool guhm-nee-dah
kkabul geomnida

Other useful forms

Honorific / Command Polite (-(으)세요)
까부세요
ggah-boo-sae-yoh
kkabuseyo
Suggestion / Let's Polite (요)
까불어요
ggah-boo-ruh-yoh
kkabureoyo
Question Polite (요)
까불어요?
ggah-boo-ruh-yoh-?
kkabureoyo?
Connective "and" — (고)
까불고
ggah-bool-goh
kkabulgo
Conditional "if" — (면)
까불면
ggah-bool-myuhn
kkabulmyeon
Progressive (고 있어요)
까불고 있어요
ggah-bool-goh ee-ssuh-yoh
kkabulgo isseoyo
Want to (고 싶어요)
까불고 싶어요
ggah-bool-goh shee-puh-yoh
kkabulgo sipeoyo
Can / Able to ((으)ㄹ 수 있어요)
까불 수 있어요
ggah-bool soo ee-ssuh-yoh
kkabul su isseoyo
Because / So (아/어서)
까불어서
ggah-boo-ruh-suh
kkabureoseo
Noun form — (기)
까불기
ggah-bool-gee
kkabulgi
Noun form — (음)
까붊
ggah-boom
kkabum