This is the 3018th most frequent Polish word.
ostrzegają
"Warn" (third-person plural form: "they warn").
In this sentence, 'ostrzegają' is used as a verb indicating the action of giving a warning or caution to others.
Ludzie ostrzegają przed silnym wiatrem.
People warn about strong winds.
Here, 'ostrzegają' is employed to advise explicitly about a specific action or behavior.
Ostrzegają nas, żebyśmy byli ostrożni na drodze.
They warn us to be careful on the road.
'Ostrzegają' functions as a verb relaying a warning about an important or systemic issue.