This is the 14584th most frequent Polish word.
przygotowują
"Przygotowują" means "they prepare" in English.
Here, 'przygotowują' is used as a reflexive verb 'przygotowują się' [preparing themselves] to indicate that the subject is engaging in the process of getting ready for something.
Uczniowie przygotowują się do egzaminu.
The students are preparing for the exam.
In this sentence, 'przygotowują' is used as a transitive verb (preparing) where the subject performs an action directed towards an object (the birthday party).
Rodzice przygotowują przyjęcie urodzinowe.
The parents are preparing a birthday party.
Here, 'przygotowują' is utilized as a transitive verb expressing the action of organizing and creating teaching materials.