This is the 2317th most frequent Polish word.
wczoraj
"Yesterday."
Temporal adverb indicating an action that occurred the day before.
Wczoraj byłem w kinie.
Yesterday, I was at the cinema.
Temporal reference used as an object of the sentence's action.
Nie pamiętam, co robiłem wczoraj.
I do not remember what I did yesterday.
Temporal usage to describe the timing of a narrated event.