- I can’t find any official statement that Aquaman can speak any language on earth.
- In addition to the languages you mention, we also saw him speak Icelandic in Justice League.
- regarding the movie, I think the Atlantean language is kind of the main language.
- there are some Atlanteans that we see who understand other languages.
- I would say all the Atlanteans, not only Arthur, they speak several languages…
It’s likely that @shreedhar’s comment doesn’t have an official source. is a comment made by the author of the article found here. Furthermore, official DC sources do not comment on his ability to speak multiple languages. It is mentioned in the link that Aquaman’s telepathy is limited to communication with aquatic creatures, so it is not a basis for any universal understanding.
Regarding the movie itself, I would say that the Atlantean language seems to be a kind of parent language from which many (if not all) other languages are derived, making it easier for them to understand other languages. i can’t find much proof regarding the atlantean language as far as dc is concerned, but using only details from the movie i think there is enough to validate my deductions! (I’m also assuming that whenever the Atlanteans talk to each other, we only hear English for the sake of the movie and they speak their mother tongue…)
obviously the main case is arthur himself, since we see him speak quite a few languages throughout the movie, as you point out; he speaks another language which we learn from the justice league when he first meets bruce in the icelandic village, not sure what language he was though…
from arthur’s mother and father, i think we can safely assume he would have learned atlantean, english and maori. anything beyond this, I’d say he would have had to “learn” on his own. however, growing up on earth and his travels may have prompted him to strive to “learn” the additional languages and they may not be effortlessly understood using Atlantean as a base.
With that counterpoint, the other main case I would say would be atlanna itself. When she meets the lighthouse keeper for the first time, we see that she is able to understand and communicate with him by speaking English. however, she seems to know nothing more about his customs or lifestyle. she believed that the fish tank was a bowl of food, that the pet/dog was a strange sight to her, and that television was also completely foreign to her.
I find it strange that he was taught a language of the “surface dwellers” (why only English?) and yet understood nothing beyond the language. in the process of learning other languages, I’d expect at least some over-reporting of details, whether from the “can you believe they do this?” or “this word has no meaning for us, but does it mean this for them?”
another case of the film refers to mere. When she and Arthur travel to Sicily, she interacts with a little girl who brings her a book about Pinocchio, referencing the earlier mention of the movie. I assume this book was written in Italian given the location. From this interaction, I think it’s safe to assume that Mere can understand Italian.
lastly, orm was able to talk to black manta, using the water hologram tech, although i guess there might be a hidden translator in the tech, so this would be the weakest example on its own…something related , black manta speaking with the elite commandos entrusted to him could fall into the same case of a translator being used during communication…
I think these are all examples from the movie of Atlanteans talking to “surface dwellers” in their own native language. obviously there was no chance of this happening underwater and these examples only involve the highborn, so it’s possible that the highborn just know or learn other languages. without further details of future comics or movies, I think we can safely say for now that Atlantean is the key to characters understanding other languages and it’s safe to say that all Atlanteans are or have the potential to be universal polyglots.