This is the 10629th most frequent Russian word.
возвращены
"Returned."
Here, 'возвращены' is used in the past tense as a passive participle meaning 'were returned', indicating that the action of returning the books was completed by someone (not necessarily specified).
Книги были возвращены в библиотеку вовремя.
The books were returned to the library on time.
In this sentence, 'возвращён' (masculine singular form) indicates that the light was brought back to its original condition as a result of someone’s action.
Свет был возвращён после ремонта.
The light was returned after repairs.
Here, 'возвращены' is used in the future-oriented sense of passive voice, conveying an obligation or expectation regarding the action of returning debts.