This is the 708th most frequent Russian word.
знать
To know.
Here 'знать' expresses familiarity or awareness of an object or place.
Я знаю этот город очень хорошо.
I know this city very well.
In this case, 'знать' is used to indicate awareness or possession of knowledge about a fact.
Ты знал, что сегодня праздник?
Did you know that today is a holiday?
Here 'знать' represents the act of acquiring or seeking knowledge regarding a specific question or topic.