This is the 7460th most frequent Polish word.
koperniku
"Koperniku" is the vocative form of "Kopernik," referring to Nicolaus Copernicus, used when directly addressing him.
The word 'Koperniku' is the vocative form of 'Kopernik,' used to directly address Copernicus in a speech or writing.
Koperniku, Twoje odkrycia zmieniły nasz sposób myślenia.
Copernicus, your discoveries revolutionized our way of thinking.
Here, 'Koperniku' is in the locative case, showing the location or topic relative to Copernicus.
Czy czytałeś kiedyś książkę o Koperniku?
Have you ever read a book about Copernicus?
In this sentence, 'Kopernika' is in the genitive case, showing possession or relation involving Copernicus.