Should I answer questions in Portuguese or English?

Question

So, other questions here on meta have addressed concerns about asking questions, and the language they should be done in.

But what about answers?

When a question is asked in English, should I respond in English? In Portuguese? In both?

What about when a question is asked in both English and Portuguese, should I answer in the same style? Prefer one over the other? Ask?

Edit

A good example being this question: Which countries and regions speak Portuguese?

And my answer: https://portuguese.stackexchange.com/a/153/59

In this case I included both English and Portuguese (portuguese first) in my answer, as the question was written with both.

Answer 1

I think we should answer questions in the same language they were asked - if someone ask something in English, it's probably because they're not too comfortable in doing it in Portuguese, so answering their question in Portuguese would be mostly useless, for them, because they wouldn't understand the answer. That said, it probably doesn't hurt to ask/answer in both languages, as you'll reach a wider audience.

Answer 2

I'm Spanish and I can read almost anything in Portuguese, but I can hardly ever write it without the help of a translator (google). I usually would try to ask in Portuguese, but to also add English; just in case I write incorrect sentences in Portuguese, you could still understand my question, and later edit it to fix any mistakes.

An answer will be valuable in any language but, as I'm trying to learn Portuguese, I would prefer, by order of usefulness, that it be in:

1- Both languages;
2- Only in Portuguese;
3- Only in English could be handy too, but less preferable.

Answer 3

Well, if the question was asked in Portuguese, answer in Portuguese. If it was asked in English, answer in English, because probably the user who asked the question in English doesn't know Portuguese very well to ask, and read and understand answers in Portuguese, or just prefered to ask in English, or wanted to reach English speakers.

If the question was asked in both languages, the OP intention is to a) reach both Portuguese and English speakers, or b) the OP wants to receive answers from anyone who could answer, whether in English or Portuguese. If you can answer in both languages, I think there's no problem in doing that.

Answer 4

Has everyone said we should answer the question with the language that was used to make the question.

The problem is, you will get questions that are duplicated but in diffrent languages, take this one for example. This question may be a duplication of the english question Do foreign acronyms take a definite article, and of which gender?

So the solution would be answering in both languages but then we got another problem, the user knows the answer in English but he doesn't knows how to write in Portuguese, this is unlikely to happen since most of the users knows how to write portuguese, but there's the other way, the user knows the answer in Portuguese but he doesn't knows how to write in English.

This takes us again to the first problem, should we really consider the questions duplicate even when they're written in diffrent languages?

To finish, we should first answer the question with the language that was used to make the question, then we could answer in the other language but only if we know to write. If we don't know how to write, the community could edit edit the answer an add the answer in the other language.
This would be a possibility but imagine long anwsers, I guess we would write in one language and then if someone else asks that question in the other language we would answer and not consider them as duplicated.