Du bist so weich = You are so soft
Wie alt bist Du? means: how old are you?
Bist du = are you (informal, singular)
"Are you with me?" That would be a translation of the question "Bist du bei mir?". The start of the sentence as in the Bach/Stölzel aria "Bist du bei mir, geh' ich mit Freuden" would be better translated as "If you are with me (or: if you're near to me), I go light-hearted (or: with gladness)".
Du bist nett = you're nice, or you're kind.
Mein guten du bist hubsch is grammatically incorrect. The correct form would be:Meine Güte, Du bist hübsch which translates as My Goodness, you're pretty.
You are fast.
You are audi
du bist - you aremein Liebchen - my darlingLiebchen is a rather old-fashioned expression, you would use mein Schatz or mein Liebling today.Du bist mein Schatz.Du bist mein Liebling.
Du bist der absolute Hammer! = You are totally awesome!
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.