This is the 2325th most frequent Polish word.
wiesz
"You know."
Here, 'wiesz' is used to mean 'you know', acting as a verb to address the person's knowledge of a fact.
Wiesz, że jesteś bardzo uzdolniony?
Do you know that you are very talented?
Here, 'wiesz' implies assurance or emphasizing the importance of recognizing a fact.
Ale wiesz, że to może być trudne?
But you know that it might be difficult?
In this sentence, 'wiesz' is also a verb meaning 'you know', asking about the person's knowledge of the location of an object.