This is the 5814th most frequent Polish word.
zamieniły
"Zamieniły" means "they changed" or "they replaced" in English.
Here, 'zamieniły się' (turned into) is used to express a transformation or change undergone by the subject (flowers).
Kwiaty w wazonie zamieniły się w suche gałązki po kilku dniach.
The flowers in the vase turned into dry twigs after a few days.
'Zamieniły' (exchanged) explains an act of swapping one item (gold) for another (silver).
One zamieniły złoto na srebro podczas wymiany.
They exchanged gold for silver during the trade.
In this case, 'zamieniły' (exchanged) is used in the context of communication to describe mutual dialogue.