This is the 2026th most frequent Polish word.
jesienią
"In the autumn."
'Jesienią' is utilized to denote the season during which a general observation about nature happens, emphasizing the cyclic characteristics of the season.
Jesienią dni stają się krótsze i chłodniejsze.
In autumn, the days become shorter and cooler.
Here, 'jesienią' refers to the season of autumn, used adverbially to indicate the time when the action takes place.
Jesienią liście zmieniają kolor na złoty i czerwony.
In autumn, the leaves change color to golden and red.
In this case, 'jesienią' specifies the time of the action, an expression of when the activity occurs.