materacu

In a sentence

• Śpię na materacu, który jest bardzo wygodny.

  I am sleeping on a mattress that is very comfortable.

  The word "materacu" here is the locative form, used after the preposition "na" to denote location.

• Znalazłem zagubiony telefon pod materacem.

  I found the lost phone under the mattress.

  In this sentence, the word "materacem" represents the instrumental case, highlighting its role in conjunction with the preposition "pod."

• Kupiliśmy nowy pokrowiec na materac w sklepie meblowym.

  We bought a new cover for the mattress at the furniture store.

  Here, "materac" is in its basic nominative form as the object of the preposition related to its direct case usage.