pies

In a sentence

• Pies biega po ogrodzie.

  The dog is running in the garden.

  Here, "pies" is used as the subject of the sentence, meaning 'dog', which is a noun referring to the animal.

• Kiedyś miałem psa, ale teraz go już nie mam.

  I used to have a dog, but I don't have it anymore.

  In this sentence, "psa" is the accusative form of "pies", used to indicate the direct object.

• Na ulicy leżał bezpański pies.

  A stray dog was lying on the street.

  Here, "pies" is used in its nominative case to describe the subject of the sentence.