"Where do your sisters go?"
Translation:Onde suas irmãs vão?
I think the more natural order (the only one, actually) in Portugal definitely is "onde vão suas irmãs". Actually, that would even be "onde vão as tuas irmãs". The general rule in questions, in several languages (french, german and also non-brazilian portuguese) is to invert the verb and the subject. African portuguese is more similar to the european one, that's why I made the distinction.
I agree. I said the general rule. I heard from a native French that they still learn in school to change the order of the verb, but that they don't do it often. Strangely, in Portugal, we sometimes do it, we sometimes don't, depending on the structure of the phrase. For example, we can easily ask "tu já fizeste o prometido?", but it does not seem proper in EP to say "onde tu vais?". I think with interrogative pronouns we always invert the verb, now that I think of it. It's just too awkward not to do it. We also use something like the French "est-ce que" (it's been ages since I used this!): "onde é que tu vais?" is perfectly normal in EP.
The verb "(eles/elas) andam" is the same as "(they) walk". In this case, the verb "to go" is "ir": "they go" is "eles/elas vão". But the "onde" is incorrect. The correct is "aonde" or "para onde". Duolingo is wrong. Ex.: "my sisters go TO _". The "a" and "para" before "onde" means the preposition "to" in english.