вук

In a sentence

• У шуми су често били чути завијање вукова.

  In the forest, the howling of wolves was often heard.

  Here, "вук" is used in its plural genitive form "вукова" to denote possession or relation—to the wolves.

• Мали дечак је био фасциниран причама о вуку као краљу шуме.

  The little boy was fascinated by the stories of the wolf as the king of the forest.

  In this sentence, "вук" is in singular nominative case, referring to a wolf as the principal subject.

• У ноћи, тајанствени вук пробијао се кроз снег.

  During the night, a mysterious wolf made its way through the snow.

  The word "вук" is here in the singular nominative case, describing an individual wolf performing an action.