Yours is a valid translation. Duo usually prefers the most obvious, though. I feel your pain. ;)
Wouldn't it be more accurate to say that the dogs are swimming is "Los perros estan nadando"?
It depends if you want to speak in generalities or of a specific time. How are the dogs spending their summer afternoons? "They are swimming" nadan What are the dogs doing right now? "They are swimming" estan nadando
Because mostly this lesson is about present tense and your answer is present continuous
Only because right now, you are learning the present tense. In language though, that can be correct way if youre talking about something the dogs do generally OR right at this moment.
The dogs are swimming should be correct just like a few questions before "Nado" accepted "I am swimming" as an answer
They do it for a reason though, sometimes there is more than one acceptable translation. Rather often, in fact.
Sometimes it writes in bold choosr ALL acceptable translation ir something like that, but ALL is bold
So your telling me I've been doing this to talk to my grandma and I'm gonna sound like a retard anyways
How is someone supposed to guess a translation of a spanish word in english the first time he sees it, like how would I know nada is swimming in english
Why I need to write an article if IN GENERAL all dogs are able to swim? If you see a group of dogs in a specific situation is not more common to use "the dogs are swimming? (I'm Learning spanish from english base, my L1 is Italian) Thanks you for your attention.