That is emphasizing that you are not young but rather something else. It's like playing a game with several people who each have a pre-determined quality and you need to find out who is tagged with which. Then you point at someone and guess, "you are the young" - but no "I am not the young one".
Your version is grammatically not wrong, but it is not really a good translation of the english sentence.
Thank you ! I always have a problem with the order of the words : I can't figure out I'm emphasizing when I make a sentence, or what others will understand if I say the right words in the wrong order.... but I guess it's just a matter of practice !
Thanks again for answering me !
@bbigblue, thank you for an amazingly clear explanation!
One comment though... you did mention further down to look at it this way: 'nem fiatal vagyok' -> '(i am) (not young)' 'nem vagyok fiatal' -> (i am not) (young)'
My problem with this is that in English both those forms mean "I am not young" (or in French "je ne suis pas jeune" or in Spanish "no soy jóven")... so, the languages that I grew up with don't have the type of nuances that exist in Hungarian.
That's why I still struggle with word order.
But your explanation above was GREAT! (Have a lingot)