"Quisque est barbarus alio"

[Quercuum]

There are a small group of adjectives that decline differently than most in the second declension. Second declension words that you would be familiar with are mostly names such as Julius, Augustus, and Livius. Adjectives such as alius are also part of the second declension, but their genitive and dative forms are slightly different.

To be fair, I would like to think that it is an easy mistake to make. For example, I have a Latin minor from my time in undergrad and having read it I didn't bat an eyelash and understood perfectly what was written. It was a simple mistake, albeit one that should not have happened.

First of all, it IS a mistake that's easy to be made; in fact, the first time I read it, I didn't notice it too.
Secondly, adjectives as "Alter (-a,-um), Alius (-a,-ud), Neuter (neutra, neutrum), Ullus (-a,-um), Nullus (-a,-um), Solus (-a,-um), Totus (-a,-um), Unus (-a,-um) etc." are called Pronominal Adjectives since they're declined, in genitive and dative, as pronouns.
So it's "Alteri" for "at/for the other one" instead of "Altero", following the common "-o" 2nd declination dative form. This is true for all these adjectives, so "Alterius, Alteri- Aliius, Alii etc."

As I've specified in my first post, "Alio" is known as a vulgar form, but I think a sentence like "Everyone is a Barbarian to someone else" is too important and significant to be written in such an incorrect and popular Latin. That's why I guess it should be reviewed.

Finally, I'd agree with who says that this sentence should be written in Greek too; but, if we do so, it would be unfair for Celtic and Punic factions. In this case, what I think has to be found is an almost neutral and universally understood language, as English nowadays it's used in European Union for interpolitical debates. That's why, in my opinion, the title and the main sentence of the mod should remain in Latin only.


Edit: It cannot even be as Philipvs Calicvla says. In fact, if it was "Everyone is a Barbarian by someone called", in Latin would be "Quisque Barbarus ab alio appellatur". (Litt: Everyone is called Barbarian by someone else). We'd lose the "est", and if we cut away the verb (Quisque Barbarus ab alio) this sentence would really sound as if it was pronounced by a non-Latin person.

Anyways, I apologize if I'm annoying everyone with these know-all Latin lessons; I just wanted to understand if there was a mistake. And I definetely think there is