아니었으니까

because it wasn't, since it wasn't

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아니 not be + 었 Past tense + 으니까 Because; since
adjective · past tense Rare #31,285
because it wasn't, since it wasn't
KO: 오늘은 일요일이 아니었으니까 가게가 열려 있었어요.
EN: Because it wasn't Sunday, the store was open.
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