Verbseoul.
descriptive

느닷없다 conjugation (neudateopda, to be sudden, to be unforeseen)

To say to be sudden, to be unforeseen politely in the present tense, use 느닷없어요 (neu-dah-suhp-ssuh-yoh) · neudaseopsseoyo. Below is the full conjugation of 느닷없다 across the three tenses and three everyday speech levels.

Grammar note (descriptive): Descriptive verbs (형용사) function like adjectives in Korean and conjugate the same way as regular action verbs. They cannot take the progressive -고 있어요 or imperative forms. 좋다 (to be good) → 좋아요; 크다 (to be big) → 커요 (으-irregular).

Conjugation table

pron. = pronunciation guide  · RR = Revised Romanization

TenseCasual (반말)Polite (요)Formal (합니다)
Present
느닷없어
neu-dah-suhp-ssuh
neudaseopsseo
느닷없어요
neu-dah-suhp-ssuh-yoh
neudaseopsseoyo
느닷없습니다
neu-dah-suhp-seum-nee-dah
neudaseoseumnida
Past
느닷없었어
neu-dah-suhp-ssuh-ssuh
neudaseopsseosseo
느닷없었어요
neu-dah-suhp-ssuh-ssuh-yoh
neudaseopsseosseoyo
느닷없었습니다
neu-dah-suhp-ssuh-sseum-nee-dah
neudaseopsseosseumnida
Future
느닷없을 거야
neu-dah-suhp-sseul guh-yah
neudaseopsseul geoya
느닷없을 거예요
neu-dah-suhp-sseul guh-yae-yoh
neudaseopsseul geoyeyo
느닷없을 겁니다
neu-dah-suhp-sseul guhm-nee-dah
neudaseopsseul geomnida

Other useful forms

Honorific / Command Polite (-(으)세요)
느닷없으세요
neu-dah-suhp-sseu-sae-yoh
neudaseopsseuseyo
Suggestion / Let's Polite (요)
느닷없어요
neu-dah-suhp-ssuh-yoh
neudaseopsseoyo
Question Polite (요)
느닷없어요?
neu-dah-suhp-ssuh-yoh-?
neudaseopsseoyo?
Connective "and" — (고)
느닷없고
neu-dah-suhp-goh
neudaseogo
Conditional "if" — (면)
느닷없으면
neu-dah-suhp-sseu-myuhn
neudaseopsseumyeon
Progressive (고 있어요)
느닷없고 있어요
neu-dah-suhp-goh ee-ssuh-yoh
neudaseogo isseoyo
Want to (고 싶어요)
느닷없고 싶어요
neu-dah-suhp-goh shee-puh-yoh
neudaseogo sipeoyo
Can / Able to ((으)ㄹ 수 있어요)
느닷없을 수 있어요
neu-dah-suhp-sseul soo ee-ssuh-yoh
neudaseopsseul su isseoyo
Because / So (아/어서)
느닷없어서
neu-dah-suhp-ssuh-suh
neudaseopsseoseo
Noun form — (기)
느닷없기
neu-dah-suhp-gee
neudaseogi
Noun form — (음)
느닷없음
neu-dah-suhp-sseum
neudaseopsseum