This is the 704th most frequent Turkish word.
siz
"You" (formal or plural).
Here, 'siz' is used as the formal/plural 'you' when addressing someone with respect or addressing multiple people.
Siz ne yapıyorsunuz?
What are you doing?
In this sentence, 'siz' functions as the formal singular/plural subject pronoun 'you,' indicating the person(s) being asked.
Siz bu kitabı okudunuz mu?
Did you read this book?
Here, 'siz' is used to formally address someone in singular, emphasizing politeness or respect.