This is the 988th most frequent Russian word.
италии
"Itалии" is the genitive or prepositional case (singular) of "Италия," meaning "of Italy" or "in Italy" depending on context.
Here, 'Италии' is in the genitive case to indicate possession.
Я изучаю культуру Италии.
I study the culture of Italy.
Here, 'Италию' is in the accusative case to indicate direction or destination.
Он мечтает о поездке в Италию.
He dreams of a trip to Italy.
Here, 'Италии' is in the prepositional case to denote location.