I was watching a German Netflix show and I cannot understand this phrase. I searched the internet and this is not an idiom. Can someone explain why the phrase, specifically the "dass aus dir mal was wird" part of the sentence was translated by Netflix as "I always knew something would become of you".
I agree with Connum about the meaning of this phrase.
"I knew there was going to come something special from (or of) you at some time."
Maybe it helps us a bit more if we try breaking it down:
wusste - knew
dass - that
aus dir - from or of you
'was - short for "etwas" = something (probably special)
wird (kommen?) - wird alone just means would, implicitly meant is probably kommen, to come : would come from (or of) you.
It's more a set phrase than an idiom. "I always knew that you would develop into a successful person" might be a better translation. That success may refer to wealth, a professional level, or even just the character of that person.
Another example would be "Was soll nur später mal aus dir werden?!" (maybe said by a parent to a rebellious or lazy teenager), loosely meaning "what are you going to do with your life" or "how are you going to achieve anything to be successful in your later life / as an adult".
Perhaps the most direct translation would be
I knew something would come of you
which is also used in English in the sense of
I knew you would become something [special, good, etc.]
The sentence would formally be
Ich wusste, dass aus dir [ein]mal [et]was wird
of which the literal translation would be
I knew, that from you once something became (would become)