This is the 547th most frequent Polish word.
gdańsku
"Gdańsku" is the locative case of "Gdańsk," meaning "in Gdańsk," a city in Poland.
The term 'Gdańsku' is in the locative case, required by the preposition 'w' (in) to indicate the location.
Mieszkam w Gdańsku od pięciu lat.
I have lived in Gdańsk for five years.
Here, 'Gdańsku' again appears in the locative case due to the preposition 'w,' denoting the location of the Old Town.
W Gdańsku znajduje się piękne Stare Miasto.
In Gdańsk, there is a beautiful Old Town.
In this sentence, 'Gdańsku' is used in the locative case with the preposition 'w.'