Mental models of languages
So as we know, children acquire their native language by being exposed to lots and lots of input in that language, internalising it, and not only memorising vocabulary but also developing mental rules (the grammar) of how that language is spoken. As such, when we come to be adults, we have a very sophisticated mental model for what’s grammatical and what’s not in our native language. As far as linguists are concerned, it is this, and not the rules handed down by style guides or generations of English teachers, that determines what is an acceptable English utterance and what is not (and the same in any other language). That’s the difference between descriptive linguistics (i.e. linguistics) and prescriptive “linguistics” (which is more of interest to English teachers, authors of style guides, etc.).
This is not to say that prescriptive linguistics has no value at all… it would be pretty difficult to teach literacy at primary schools if the answer to everything was just “well I don’t know, what do *you* think sounds right?“, not to mention trying to teach second-language learners. And if you’re writing for publication, you know, you do usually have to use a standardised form of the language and not just whatever sounds right in your head. Realistically, I think through education most English speakers develop two mental models – we can distinguish between “what sounds right in standard English”, “what sounds right in informal English (encompassing dialect, sociolect, etc.)” and “what is wrong English”. This is far from unique – there are many languages where the difference between the standard and colloquial forms of the language are very well-acknowledged – but in English they’re often ignored (except when a dialect is especially divergent from standard English, like AAVE or Scots). But I mean, my personal speech (my idiolect) is not very divergent from standard Australian English (I don’t say “youse” or anything like that haha) and it still has some differences, like my use of double object pronouns. There are other things too, like how in colloquial English you can often drop pieces like the subject pronoun and copula, which you can’t do in the standard. Like when my partner has a look of mischievous glee on his face as he stares at his phone, I can ask, “You trolling people on Facebook again?” In standard English there should have been a copula – ‘are’ – in there, but in colloquial speech I can drop it and it’s not ungrammatical (now if I’d said “Trolling be you people on Facebook again?”, that would be ungrammatical).
Anyway, I’ve rambled on this far about native languages. But something I also find interesting is the way that we build up mental models of second (and third, fourth, etc.) languages too. That is, after some time learning an additional language we don’t just produce it through sheer memorisation of rules, we actually develop a “gut feel” for what sounds right and wrong, in the same way we did as children for our native one(s). This is one of the reasons that learners are recommended to consume vast amounts of media (TV, film, books, podcasts, etc.) in their target language – the more input you get, the less likely it is you’ll form mental models that are wrong!
Because that’s the thing, of course. When you learn a new language, you can develop mental models with errors. I know I have some of these with Spanish – for example, I can “gut feel” the genders of probably 98% of words, but because my “gut feel” is just “all the word endings have to match!!” I make mistakes. By “match” I don’t just mean o’s and a’s – other endings that pretty reliably signal one gender or the other – -ción, -dad, -or, etc. – are definitely in my brain as masculine or feminine endings. But e’s are often crapshoots (you’ve just gotta memorise, so if it’s not a common word IDK, and in the case of "el arte" even though it’s a common word still IDK because I’ve seen Museo de Bellas Artes too many times) and anything with an ending that suggests the opposite of its actual gender – "el tema", "la mano", "el sistema" absolutely does my head in. I’ll usually get the article right because that’s how you memorise the word, but I’ll try making adjectives match the ending instead. So like, "el planeta lejana" instead of "el planeta lejano", or "el sistema católica" instead of "el sistema católico". And if I’m reading something that someone has written in actual correct Spanish, and I see a “mismatch” like "sistema católico", my brain will be like !!!WARNING!!! even though it’s my brain that is wrong and the actual Spanish speaker that is correct. I think the only to “fix” this is just way more reading/watching/listening about planets and systems and dramas and so on. But still, it’s cool to me that I can go from knowing zero of a language (12 years ago) to having that ingrained sense of what’s right and wrong in it, even if it’s imperfect.
But then, here is a related topic that interests me. Obviously when it’s just me by myself making mistakes in Spanish, that is a mistake. But when you have a whole ton of non-native speakers speaking English the same way, even though it’s a way that native English speakers mostly think sounds “wrong”, it actually becomes kinda right. For example, you have this concept of Euro English, or the English spoken by non-native speakers in Europe (often at an extremely high level, of course!). I think the vocabulary section of the Wikipedia article conveys the differences from standard English really well. Now I’m sure there are a huge number of Europeans who take pride in never making “mistakes” like this, so please don’t think I’m insinuating every non-native English speaker in Europe speaks like this 😉 But umm, from having known many people from countries like Spain and France, some of these immediately ring a bell for me. And honestly, these kinds of uses don’t sound any more wrong to me than some of the things said in certain US dialects… like “the car needs washed” or “I might could do something” sound worse to my ears, even though I know they’re legitimate in some dialects. So I guess to me, “Euro English” has come to sound like a perfectly legitimate dialect of English, rather than like, “a collection of common mistakes”.
Another point of comparison would be Indian English. You will (rightly) not hear many people say that Indian English is just “full of mistakes” where it differs from standard English! And yet it, too, is largely spoken by second-language speakers (if often, like in Europe, people who are so good at English that they’re functionally bilingual, but it’s still not their mother tongue). Again, most of the Indian English vocabulary listed on Wikipedia is immediately understandable to me, it just sounds like a dialect I don’t speak. And considering the very long history of English in India, its use in many standardised media there (like TV news, newspapers, etc.) and the fact that there are 130 million English speakers in the country (making it the second-largest national supradialect after American English!) I’m pretty sure everyone who knows what they’re talking about recognises Indian English as a legitimate dialect and not “people speaking English wrong”. (Also, I have to respect Indian English as there are some things on which it’s apparently the only other dialect that accords with Australian/NZ standards, like using the word “capsicum” for what Americans call bell peppers, or spelling chilli with two Ls and pluralising it “chillies”.)
The point I’m trying to make is that there is a tipping point whereby learners’ mental model of a language ceases to be “mistaken” and starts to be “a new dialect”. Sort of similar to how a pidgin becomes a creole, except creoles have native speakers and these varieties have very few of those (Indian English is estimated to be the first language of just 260,000 people, for example – approx. 0.2% of all the dialect’s speakers). But still, there must be a point where the same mental model of, say, English is shared by enough people that it comes to be a new, definable variety. And seeing as how for natives, our local dialects don’t replace our knowledge of standard English, there’s no reason it has to be the case for these varieties either – that is, Euro English doesn’t have to be at odds with standard English; someone who speaks perfectly excellent standard English might still code-switch between the two depending on the crowd they’re with. And as someone with a linguistics background, I love all the variety in the English language, including the influence of other languages on ours. I’ve never seen why learners of English should be expected to choose a native dialect and try to mimic it perfectly… speaking awesome English doesn’t just mean people who speak like BBC newsreaders. And speaking good English doesn’t mean phrasing everything exactly like a native would.
I think I have to apologise that this post has been all over the place. The thought bubble that got me rolling was just about how we acquire and store mental models of the languages we speak, and this is an interesting little NYT article from 1997 about that. The grammars of the languages we speak from childhood are stored in a part of the brain called Broca’s area, but when we learn a language in adolescence or later, it doesn’t go in that same area – the brain creates a kind of ancillary Broca’s area next to the first one. But that’s still kind of impressive to me – we create a new Broca’s area from scratch? Wow! The brain is truly incredible.
 English Wikipedia - Euro English - Vocabulary
 English Wikipedia - Indian English - Vocabulary
 New York Times - When an Adult Adds a Language, It's One Brain, Two Systems