This is the 5269th most frequent Polish word.
rozpoczęli
"Rozpoczęli" means "they began" or "they started."
The word 'rozpoczęli' here refers to the action of starting or beginning something important, in this case, the classes.
Studenci rozpoczęli zajęcia o dziewiątej rano.
The students started the classes at nine in the morning.
In this sentence, 'rozpoczęli' demonstrates the initiation of a scheduled or organized activity, like the training.
Drużyna rozpoczęła trening w siłowni.
The team started the training in the gym.
Here, 'rozpoczęliśmy' pertains to our group's initiation of a project, denoting the start of an endeavor or undertaking, emphasizing the active involvement.