This is the 2101st most frequent Russian word.
петербурге
The word "петербурге" means "in St. Petersburg" in English.
In this sentence, 'петербурге' is used in the prepositional case after the preposition 'в' to indicate location.
Я когда-то жил в Петербурге.
I once lived in Petersburg.
Here, 'петербурге' again appears in the prepositional case, indicating the place associated with the activity.
Моя семья планирует поездку в Петербурге.
My family is planning a trip to Petersburg.
The usage of 'петербурге' in this sentence is in the prepositional case, used to describe characteristics of the location itself.