English Translation
From now on, you’re one of us.
Why is it “bist du” and not “du bust”
From now on, you’re one of us.
Why is it “bist du” and not “du bust”
German is a V2 language, and the expression “von nun an” occupies the first slot.
Morbrorper’s advice to follow the V2 rule (n German the flexed part of the verb occupies the second spot in a main clause) is absolutelly correct.
Compare:
Du bist eine von uns.
Von nun an bist du eine von uns.
Ich sage, dass du von nun an eine von uns bist.
Du hast eine von uns angegriffen.
I may add that mistakes in word order are amongst the most common for non-native speakers in German. So common that e.g. a screen writer, who wants to characterize a person as a non native speaker or maybe as a badly educated second generation immigrant, will use just word order mistakes.
In the German edition of “Asterix bei den Briten” the Britons are speaking correct German but with English word order thus making them immediately recognizable as “British” even for a child.