One class of linguistic questions I see a lot is “Why does John Doe say X when it doesn’t make any logical sense?” This is usually in reference to a new idiom, dialect or language the questioner is encountering. The answer is that while grammar is usually consistent, it doesn’t always follow real world logic. Even worse, there are lots of idiosyncratic quirks that happen “just because”.
A recent one was – if people from Korea speak Korean, why don’t people from Japan speak *Japanian (instead of Japanese). And why do the Basque speak just Basque and not *Basqu(i)an, *Basquese or even *Basquish. It’s a mystery. You can solve some of it by saying that the –ish/-sh/-ch ending is older and tends to be used with languages closer to Britain (e.g. English, Spanish, Welsh, Irish, French (aka Frankish)). But do you really think the average adult has even connected language names with history of the Anglophone world? No – it’s just memorized.
Ironically, non-standard dialects can actually be more logical, yet will still be dismissed as “poor grammar”. After all, if we say her pen but that pen is hers and our building and that that building is ours…shouldn’t we also say that pen is mines (like they do in Baltimore). Logically…yes. But I think we all know what happens to the poor student who uses mines in an essay – and it’s not an A+ for logic.
This is an unsettling concept because so many writers and speakers do use language to construct effective, logical arguments. Shouldn’t the bones of language (vocabulary and grammar or syntax and morphology) also be equally logical. The surprising answer is that while grammar can have a system, it’s not one that is “logical”. To me this is a powerful reason to think grammar is not directly connected with “general cognition”.
I mean, who in their right mind would invent a language with as many irregular past tense verbs as English has? Ugh!