Something occurred to me last night.

Water is not a good place for paper or writing tools. I know, shocking, but it's just one of those things we take for granted.

Now, in Equestria, we can assume that when they aren't feeding on emotional strife, Sirens are mostly aquatic.

When the Dazzlings were banished, we can probably assume that they didn't immediately go to school. Assuming that Canterlot High is in North America, they would have arrived at a time when there were a number of highly developed agricultural American Indian civilizations, and Viking voyager Leif Eiriksson visited and settled an area called Vinland (the northern tip of Newfoundland).

Not exactly the best upbringing for learning to read and write.

Now, i'm sure over the years, they might have learned to recognize a few words (insert "Adagio/Aria complaining about the language changing every century" joke), but we can reasonably guess they learned about human culture mostly through observation.

Interestingly, it seems all the Dazzlings actually did during their stay at Canterlot High was further their plan, rather than any actual schoolwork too, but then again there seem to be very few actual classes at that school, so this probably doesn't count for much.

Do I have a point? did I miss something? am I taking this too seriously?

3975849
It's an interesting theory, assuming your presumptions about them being illiterate are true, but I think there may be an alternative explanation.

What if the Sirens were not only transported to a new world, but also moved through time as well? Remember that in the episode "It's About Time", when Twilight went back through time, she also went through space (she started in the Canterlot Archives, then ended up back in the tree library). When Star Swirl banished the Sirens with the portal, maybe it thrust them hundreds/thousands of years into the future in the human world. After all, the movie mentioned that Star Swirl wasn't 100 percent sure where the portal went. If this was the case, they wouldn't know how to read or write because they had (from a relative standpoint) just arrived in that world and had no time to learn how to read and write. This would also explain why they hadn't aged much in the human world.

The only problem I have with the illiteracy theory is that Twilight is shown understanding things written in the human world in both of the EG movies. One could therefore assume that both worlds share the same languages or are at least similar enough that she could guess the meaning (sort of like how someone who speaks Dutch can, with effort, understand someone speaking German, since they're in the same language family). Then again, maybe the period of Equestria when Star Swirl was around had a different language system, so the Sirens legitimately couldn't read anything either.

But it's still an interesting theory you've got.

3975849
It's an idea that you could probably sell with some effort in a story.

Sonata displayed the ability to read in the movie though. She could read the posters to know it was Taco Tuesday.

3976934 I'm not saying they're COMPLETELY illiterate, they can still read a little, considering they've been stranded there 1000 years or so.

3976934 3976968 Maybe she just saw the tacos on the poster on a Tuesday and put two and two together?

3978197 good point, as remember, the cafeteria was strangely devoid of tacos...

3975849 I am pretty sure that they learned to read at some point after their banishment. It's also been quite a while since the last time I saw you around Changeling.

3975849

Well, they'd probably communicate by carving on stone underwater, but Siren writing characters probably look nothing like Roman ones, so, yeah, learning to read English was probably not especially easy at first for them.

3975914

Re Twilight's ability to read in the human world, it's possible that whatever force changes her body from pony form to human form when she passes though the portal (and bizarrely also assigns her an outfit), also changes those parts of her brain responsible for literacy.

3978526

That could be the case, but I doubt that. The reason being that even when Twilight isn't around, the words that we can see look very similar to the style of writing in Equestria. If it was just a matter of her perception, then any scene without Twilight should have shown the letters in a slightly different manner; since this wasn't the case, one could assume that both world shared an alphabet and writing style.

3975849 3978436 I dunno though...

It would have been inconceivable for them to have moved through much of history without them being able to adapt to their surroundings, so it's highly unlikely that they are illiterate. Also, if they were so, going to Canterlot High would have been a very poor choice, as they would have been exposed at once. They have blended in well there, so they must have had education for them to blend into CHS. Adagio seems intelligent as well, so she doesn't seem to be exactly illiterate. Even someone like Sonata seems to be educated, so they don't seem to be the uneducated type.