This is the 3097th most frequent Polish word.
pracowało
"Pracowało" means "worked" (third person singular or neuter singular past tense).
The word 'pracowało' here is used in the past tense (third-person plural neuter form) to indicate a group of people were employed or engaged in a task at the factory.
Wiele osób pracowało w tej fabryce.
Many people worked in this factory.
Here 'pracowało' conveys that the device was functioning or operating, again in past tense, showing it had issues.
To urządzenie nie pracowało poprawnie.
This device was not working correctly.
In this sentence, 'pracowało' is used impersonally with 'się,' referring to general activities in the past, particularly the hard work on farms.