그러니

In a sentence

• 시간이 늦었으니 쉬도록 하세요.

  It is late, so you should rest.

  Here, '그러니' is derived from '그러하니', meaning 'so' or 'therefore', to connect the situation of being late with the advice to rest.

• 모두 알고 있으니 조용히 해 주세요.

  Everyone knows, so please be quiet.

  In this case, '그러니' functions to indicate a reason (everyone knows) leading to a request (being quiet).

• 그는 이미 답을 알고 있었으니 시험은 잘 볼 거예요.

  Since he already knew the answers, he will do well on the test.

  Here, '그러니' signifies cause and effect, linking the prior knowledge of answers with the expected success in the test.