-으니

• 니 (-ni) – after vowels and ㄹ (l), for all suffixes below

• (SK Standard/Seoul) IPA^(key): [ɯni]
• Phonetic hangul: [으니]

From Middle Korean -으〮니〮/ᄋᆞ〮니〮 (Yale: -úní/óní), from Old Korean 隱 (*-un, realis gerund marker) + 是 (*-i, either the nominative case marker or a semantically light noun).[1]

으니 • (-euni)

1. because, since, as; used to convey a cause, a proof, or a premise.

   Synonym: 으니까 (-eunikka)

   워낙 배가 고팠다 보니 무엇을 먹어도 맛있었다.

   Wonak bae-ga gopatda bo-ni mueos-eul meogeodo masisseotda.

   Everything tasted good since I was so hungry.

   시절이 하 수상하니 어찌 될지 몰라라.

   Sijeor-i ha susangha-ni eojji doelji mollara.

   As the times are so treacherous, I do not know how things will end up.

2. as; used to convey a relevant fact, such an immediately antecedent action which enables the subsequent clause.

   Synonym: 으니까 (-eunikka)

   바닷가에 다다르니 하늘이 노을에 물들던 참이었다.

   Badatga-e dadareu-ni haneur-i no'eur-e muldeuldeon cham-ieotda.

   When we arrived at the seashore, the sky was starting to glow with the sunset.

• In spoken language, the emphatic form 으니까 (-eunikka) is usually used.

으니... 으니 • (-euni... -euni)

1. Alternative form of 느니 (-neuni); see Usage notes in that entry.

으니 • (-euni)

1. Alternative form of 느니 (-neuni); see Usage notes in that entry.