It means "Short question, are you in Berlin?"
Bist du = are you (informal, singular)
Wie alt bist Du? means: how old are you?
Du bist nett = you're nice, or you're kind.
You are fast.
You are audi
Du bist der absolute Hammer! = You are totally awesome!
Du bist so weich = You are so soft
You're a gem
In English: "You're an idiot."In Deutsch: "Du bist ein Idiot."Or "Du bist ein Dummkopf".Please note proper spelling of "you're" in the English.
Du bist schön.
It means "When will you be at home?"
translated it means are you ready