"Aren't you coming too?"

"Yes...I mean, no? I mean, yes, I'm coming."

When answering a normal, positive question, you're unlikely to fumble around like this. If the question is "are you coming too?" it's pretty clear that "yes" means "I am coming" and "no" means "I'm not coming."

But when you hear a negative question — "aren't you coming too?" — everything falls apart. Does "yes" mean "yes, I'm coming" or "yes, I'm not coming?"

The proper way to give a positive answer to a negative question is one of the many perplexing ambiguities of the English language. But it wasn't always this way. In Middle to Early Modern English (approximately Chaucer to Shakespeare), there were four forms, one for each type of answer, which would have been found in the following contexts:

Comest thou?

Yea / Nay

Comest thou not?

Yes / No

This four-form system is still used in modern Romanian; however, by around Shakespeare's day, the English distinctions between yea and yes, and nay and no, started to become less robust, and fairly soon afterwards they started collapsing to our present, two-form system, complete with the confusion around negative questions.

Other languages have their own ways to get around this dilemma. For example, both French and German have a separate word for this situation. In French, there's the basic oui and non for answers to positive questions, but then there's also si and non for answers to negative questions. For example, here's "are you coming with us" and "aren't you coming with us" in French, with the negative part bolded:

Tu viens avec nous?

Oui / Non

Tu ne viens pas avec nous?

Si / Non

German is very similar. For answers to positive questions, there's ja and nein. But for answers to negative questions, there's doch and nein, as we can see in the same pair of questions below:

Kommst du mit?

Ja / Nein

Kommst du nicht mit?

Doch / Nein

Since negative questions are a lot less common than positive questions, si and doch aren't as well known as oui and ja. But they're still very useful for speakers of French and German (as well as Hungarian and the Scandinavian languages) to avoid confusion when answering negative questions.

Unfortunately, English has no special words for answering negative questions. But there is another workaround, if you want to take a cue from Latin, Finnish, Gaelic, or Mandarin. Since these languages don't use particular words for "yes" or "no" at all, speakers normally repeat the verb, either in its positive or negative form, or, as in Latin, pick from a larger variety of adverbs. The English equivalent of this strategy would look something like this:

Are you coming?

I am / I'm not / Certainly / Of course / Never / No way

Aren't you coming?

I am / I'm not / Certainly / Of course / Never / No way

So there you have it. If you want to be very clear about your response, this strategy is probably the best, most efficient way to answer a negative question without confusion.