Verbseoul.
하다 verb (adj)

불가능하다 conjugation (bulganeunghada, to be impossible)

To say to be impossible politely in the present tense, use 불가능해요 (bool-gah-neung-hae-yoh) · bulganeunghaeyo. Below is the full conjugation of 불가능하다 across the three tenses and three everyday speech levels.

Grammar note (하다 verb (adj)): 하다 adjectives use the same verb 하다 as a suffix to turn descriptive nouns into predicates (행복하다 = to be happy). They conjugate identically to 하다 verbs: the 하 contracts before -아/-어 suffixes to give 해. 행복해요, 행복했어요, 행복합니다. See all 하다 verbs →

Conjugation table

pron. = pronunciation guide  · RR = Revised Romanization

Highlighted = where the stem changes

TenseCasual (반말)Polite (요)Formal (합니다)
Present
불가능해
bool-gah-neung-hae
bulganeunghae
불가능해요
bool-gah-neung-hae-yoh
bulganeunghaeyo
불가능합니다
bool-gah-neung-hahm-nee-dah
bulganeunghamnida
Past
불가능했어
bool-gah-neung-hae-ssuh
bulganeunghaesseo
불가능했어요
bool-gah-neung-hae-ssuh-yoh
bulganeunghaesseoyo
불가능했습니다
bool-gah-neung-hae-sseum-nee-dah
bulganeunghaesseumnida
Future
불가능할 거야
bool-gah-neung-hahl guh-yah
bulganeunghal geoya
불가능할 거예요
bool-gah-neung-hahl guh-yae-yoh
bulganeunghal geoyeyo
불가능할 겁니다
bool-gah-neung-hahl guhm-nee-dah
bulganeunghal geomnida

Other useful forms

Honorific / Command Polite (-(으)세요)
불가능하세요
bool-gah-neung-hah-sae-yoh
bulganeunghaseyo
Suggestion / Let's Polite (요)
불가능해요
bool-gah-neung-hae-yoh
bulganeunghaeyo
Question Polite (요)
불가능해요?
bool-gah-neung-hae-yoh-?
bulganeunghaeyo?
Connective "and" — (고)
불가능하고
bool-gah-neung-hah-goh
bulganeunghago
Conditional "if" — (면)
불가능하면
bool-gah-neung-hah-myuhn
bulganeunghamyeon
Progressive (고 있어요)
불가능하고 있어요
bool-gah-neung-hah-goh ee-ssuh-yoh
bulganeunghago isseoyo
Want to (고 싶어요)
불가능하고 싶어요
bool-gah-neung-hah-goh shee-puh-yoh
bulganeunghago sipeoyo
Can / Able to ((으)ㄹ 수 있어요)
불가능할 수 있어요
bool-gah-neung-hahl soo ee-ssuh-yoh
bulganeunghal su isseoyo
Because / So (아/어서)
불가능해서
bool-gah-neung-hae-suh
bulganeunghaeseo
Noun form — (기)
불가능하기
bool-gah-neung-hah-gee
bulganeunghagi
Noun form — (음)
불가능함
bool-gah-neung-hahm
bulganeungham