This is the 5411th most frequent Polish word.
stwierdzili
"Stwierdzili" means "they stated" or "they concluded."
Here, 'stwierdziliśmy' is used in the sense of stating or determining. It emphasizes the action of coming to a conclusion about a matter.
Stwierdziliśmy, że plan trzeba zmienić.
We concluded that the plan needs to be changed.
In this context, 'stwierdzili' is used to indicate confirmation or verification by experts.
Eksperci stwierdzili obecność rzadkiego minerału.
Experts confirmed the presence of a rare mineral.
The use of 'stwierdzili' here means making a statement or observation about the situation.