другу

In a sentence

• Ишао сам у парк са свом најбољем другу.

  I went to the park with my best friend.

  Here, 'другу' is in the dative case, used to indicate the indirect object of the sentence, showing with whom the subject (I) went to the park.

• Књигу сам вратио свом другу.

  I returned the book to my friend.

  'Другу' appears in the dative case again, showing to whom the book was returned, serving as the indirect object of this action.

• Објаснио сам све проблему свом другу.

  I explained everything about the problem to my friend.

  In this sentence, 'другу' also in the dative case specifies to whom the explanation was directed, functioning as the recipient of communication.