How does one say "It's not nothing."

Question

In English, we can express the idea that something is not negative, such as:

A: What's in the box?
B: Oh, nothing.
A: It's not nothing!

In English, the double negative (not and nothing) conveys the idea that we are negating the "noting" said by person B. In Spanish, though, double negatives don't work the same way. A word-for-word translation would result in:

A: No es nada!

Which means "It is nothing" not "It is not nothing."

The same phenomenon is found in other contexts, as well, any time we would intentionally use a double negative to indicate a positive (as opposed to when a double-negative is unintentionally used, as is also often done).

How can one express the double-negative meaning that is present in the English original?

Answer 1

The former answer is correct, but I'll try to enter a litle bit more in detail as to why the confusion exists.

The use of nada requires in some some cases a double negation: "No es nada", "no me dijo nada" etc. I cite DPD:

cuando [la palabra "nada"] va pospuesto al verbo exige que este vaya en forma negativa, precedido del adverbio no, o, si no, que haya en la oración algún otro elemento negativo (jamás, nunca, nadie, etc.) [...] pero si va antepuesto al verbo, este no debe ir en forma negativa

(what was already discussed in this question)

Using a double negative in English makes a sentence "positive" again. In Spanish, a double negation enforces the negation. Therefore one can say, the exact English double negation doesn't exist in Spanish. Solutions to express the same are:

• Using "nada" before the verb (as it doesn't need the additional negation): "No, nada no es"

• Make it immediately positive to avoid problems: "No, hay algo"

• In the spoken form it's natural to me (and apparently people agree, looking at my comment) to say "No, no es nada"(!). Although grammatically it is an error (somehow related to the meaning of "nunca nadie"?).

• Also using a different tone (which Alexis mentioned and which sounds natural to me) is grammatically wrong. Putting the emphasis on the word "nada" would make it sound as if it were empty, while the emphasis on "no" would (in the context of this conversation) negate the previous sentence and therefore mean that there is something or not nothing.

Here you can find an article on the topic.

Answer 2

As @Alexis pointed out in his comment, the inflection is very important here. In fact, even your translation "No es nada" could sound not too strange with the correct inflection...

Anyway, I think I'd say something like:

A: ¿Cómo que nada?

or

A: No, algo hay.

or

A: No, nada no es.

Answer 3

A: What's in the box?
B: Oh, nothing.
A: It's not nothing!

A: ¿Qué hay en la caja?
B: Oh, nada.
A: No, no es nada. or No es nada.

This is a possible translation but you have to say it with a specific intonation:

1. "No, no es nada."

A longer pause after the comma and "es" sounds high, more acute and soft. But meaning is usually conveyed via facial expression.