This is the 2632nd most frequent Polish word.
zbigniewa
"Zbigniewa" is the genitive or accusative singular form of "Zbigniew," a Polish male given name.
'Zbigniewa' is used in the genitive case indicating possession.
Czy widziałeś książkę Zbigniewa?
Did you see Zbigniew's book?
'Zbigniewa' here is used in a different form to indicate the person receiving the action.
Podarowałem prezent Zbigniewowi.
I gave the gift to Zbigniew.
This shows the word in the accusative case as the direct object of the action.