This is the 72nd most frequent Polish word.
kiedy
"When."
Used to ask about a specific time something occurs.
Kiedy zaczyna się film?
When does the movie start?
Used to describe a time in the past.
Kiedy byłem młody, chodziłem na wiele pieszych wycieczek.
When I was young, I went on many hikes.
Used within a sentence to indicate uncertainty about a time.