This is the 5574th most frequent Polish word.
ustalają
"Ustalają" means "they establish" or "they determine."
Here, "ustalają" means "establish" or "determine," indicating that teachers decide or set the curriculum.
Nauczyciele ustalają program nauczania na nowy rok szkolny.
The teachers establish the curriculum for the new school year.
In this sentence, "ustalają" is used as "agreeing on" or "finalizing," pertaining to arranging or confirming a specific time for the meeting.
Ustalają termin spotkania w dogodnym dla wszystkich czasie.
They are agreeing on a time for the meeting that is suitable for everyone.
Here, "ustalają" refers to "setting" or "defining," relevant to deciding upon rules collectively in a casual or playful context.