Verbseoul.
하다 verb (adj)

행복하다 conjugation (haengbokhada, to be happy)

To say to be happy politely in the present tense, use 행복해요 (haeng-boh-kae-yoh) · haengbokaeyo. Below is the full conjugation of 행복하다 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
행복해
haeng-boh-kae
haengbokae
행복해요
haeng-boh-kae-yoh
haengbokaeyo
행복합니다
haeng-boh-kahm-nee-dah
haengbokamnida
Past
행복했어
haeng-boh-kae-ssuh
haengbokaesseo
행복했어요
haeng-boh-kae-ssuh-yoh
haengbokaesseoyo
행복했습니다
haeng-boh-kae-sseum-nee-dah
haengbokaesseumnida
Future
행복할 거야
haeng-boh-kahl guh-yah
haengbokal geoya
행복할 거예요
haeng-boh-kahl guh-yae-yoh
haengbokal geoyeyo
행복할 겁니다
haeng-boh-kahl guhm-nee-dah
haengbokal geomnida

Other useful forms

Honorific / Command Polite (-(으)세요)
행복하세요
haeng-boh-kah-sae-yoh
haengbokaseyo
Suggestion / Let's Polite (요)
행복해요
haeng-boh-kae-yoh
haengbokaeyo
Question Polite (요)
행복해요?
haeng-boh-kae-yoh-?
haengbokaeyo?
Connective "and" — (고)
행복하고
haeng-boh-kah-goh
haengbokago
Conditional "if" — (면)
행복하면
haeng-boh-kah-myuhn
haengbokamyeon
Progressive (고 있어요)
행복하고 있어요
haeng-boh-kah-goh ee-ssuh-yoh
haengbokago isseoyo
Want to (고 싶어요)
행복하고 싶어요
haeng-boh-kah-goh shee-puh-yoh
haengbokago sipeoyo
Can / Able to ((으)ㄹ 수 있어요)
행복할 수 있어요
haeng-boh-kahl soo ee-ssuh-yoh
haengbokal su isseoyo
Because / So (아/어서)
행복해서
haeng-boh-kae-suh
haengbokaeseo
Noun form — (기)
행복하기
haeng-boh-kah-gee
haengbokagi
Noun form — (음)
행복함
haeng-boh-kahm
haengbokam