Nothing or anything?
In Spain, we say, for example: "No quiero nada". "I don't want nothing" (nothing = nada)

In english I think is right to say: "I don't want anything" (anything = algo) or is correct "I don't want nothing"?

Is the same question: "There isn't anybody" or "There isn't nobody"?

Question

Nothing or anything?
In Spain, we say, for example: "No quiero nada". "I don't want nothing" (nothing = nada)

In english I think is right to say: "I don't want anything" (anything = algo) or is correct "I don't want nothing"?

Is the same question: "There isn't anybody" or "There isn't nobody"?

Answer

If the statement is negative, use anything: I don't want anything.
If the statement is affirmative, use nothing. I want nothing. 
I didn't see anybody. 
I saw nobody.
There isn't anybody there. 
There's nobody there.
http://learnenglish.britishcouncil.org/en/english-grammar/pronouns/indefinite-pronouns

Answer

The same goes for "there isn't nobody". It's a double negative.

Answer

I don't want nothing in English is a double negative. It's actually means that you do want something although people will know that you actually mean to say "I don't want anything". We try to avoid using double negatives in English.

Ne manquez pas cette occasion d'apprendre une langue depuis chez vous. Découvrez notre sélection de professeurs de langues expérimentés et inscrivez-vous dès maintenant à votre premier cours !