Should be "on my balcony" only, unless "Na" can mean "close to but not necessarily standing on" my balcony. Romeo stood at Juliet`s balcony (he was below it too, but also at it) and Juliet was at her balcony even before had stepped on to it. "At" would convey a sense of attendance or duty or expectation or regularity at the space where the balcony was. Hope you understand. By the way I am British. Perhaps other native speakers have a different feeling about the difference between "at" and "on". In some contexts "at" and "on" would be interchangable, like, for example "Knock on the door" or "Knock at the door". But I would say that in this balcony case, "at" and "on" convey meanings that differ well beyond interchangability.
Ah, I see. Thanks for the explanation, the uses of "at" and "on" were always a bit confusing to me.
It's actually a region thing. Some places say "varanda", some say "sacada". Where I live, in the south, we never use "varanda", for example C:
I live in São Paulo and sacada is extremely common and mostly used for apartments.
"Sacada" and "varanda" are different things. "Sacada" is balcony, "varanda" is porch.
That is in English. Portuguese is a different language and in Portugal they do not have balconies but almost every room, no matter what floor it is on, has a varanda (not the same as the English "veranda").
As a native speaker of English, I would NEVER say "In my balcony", which is suggested as correct alternative by duolingo.
As someone who did a European Portuguese course previously, duolingo disallowing European Portuguese is rather annoying. Also varanda is much easier to remember!
No it should be "Na minha varanda" balcony = veranda in portuguese from PORTUVGAL