Que te voy a decir que tu no sepas

Que te voy a decir que tu no sepas
 

in English?

What am I going to tell you that you already do not know.

sI, ya pero es una frase que se usa en inglés para abreviar una conversación o confirmar algo?

Sí.

o para copuchar un poco más... :D

I'm telling you, you know nothing:thumbsup:.(you don't know nothin'):warning:(NADA FORMAL)
You don't know diddly(parece del campo)
You don't know dick :warning:(VULGAR)
You are clueless/you are without a clue:thumbsup: (más nuevo-dicho por jovenes)

Poli I think you misunderstood , I suppose I didn´t express myself right.

"What can I tell you that you don't already know?" is a pretty common phrase that happens to be almost a literal translation.

However, I think you're looking for something like "Let's cut to the chase. (Ir al grano.)" Instead of beating around the bush (dando rodeos), we get right to the point (the important matter) - we get down to the nitty-gritty.

In faCT I was looking for "What can I tell you that you don't already know?", thank you.

can already go at the end of the sentence, somehow or other it sounds better to me.
"What can I tell you that you don't know already ?"

It can go in either place. It sounds better to me in front of the verb.

It would still be grammatical if the adverb came after the verb, but it sure sounds strange.