생일을

In a sentence

• 저는 친구의 생일을 축하해 주었어요.

  I celebrated my friend's birthday.

  In this sentence, '생일을' is used as a direct object for the verb '축하하다', which means 'to celebrate.' It refers specifically to the birthday being the event celebrated.

• 저는 지난주에 생일을 보냈어요.

  I spent my birthday last week.

  Here, '생일을' acts as the direct object of the verb '보내다', meaning 'to spend.' It indicates the occasion that was spent.

• 그녀에게 특별한 선물을 생일을 기념하여 주었어요.

  I gave her a special gift in commemoration of her birthday.

  In the third example, '생일을' serves as part of the phrasing '생일을 기념하다,' which means 'to commemorate the birthday.' It highlights the occasion being honored.