This is the 41st most frequent Polish word.
były
"Były" means "former" or "ex" in English.
In this sentence, the word 'były' refers to something from the past, describing past events.
Były czasy, kiedy wszystko było inne.
There were times when everything was different.
Here, 'były' is an adjective used to describe someone's previous status or occupation.
On jest były żołnierz.
He is a former soldier.
In this context, 'byłyśmy' is the feminine plural past tense form of 'to be' used with a specific subject.