I mean, how hard can it be? When in Rome, speak Roman, and when in America, speak American. You know the sort of thing: you say tomato, they say Heinz; you say potato they say fries. It's cultural integration 101, but apparently some people didn't get the memo. Luckily for those people, there's Twitter, which is awash with helpful sorts imparting advice such as: "If your in America and can't speak English then you shouldn't own a donut shop." There are, indeed, so many nouveau nativists defending the sanctity of American English while simultaneously slaughtering it that they've spawned their own Twitter-bot.

Set up last Friday, @YourinAmerica is devoted to responding to Joycean formulations such as "I really hate when people sitting near us speaking in a foreign language your in America you speak American", with concise lessons on the use of your versus you're. The account, which now has over 12,000 followers, seems to have struck a cultural chord. It gained nearly 8,000 followers in three days just from the repetition and reiteration of a basic rule of grammar, albeit with a few snarky hashtags thrown in. Meanwhile, many of the people posting the offensive remarks have swiftly deleted them. Grammar fascists 1, fascists 0.

While it may have a sic sense of humour, @YourinAmerica is the best thing on Twitter since the please-don't-engage-Donald-Trump-bot, particularly as the mentality it positions itself against is far from being isolated online. With its Hispanic population growing rapidly, large (and largely white) swaths of the US have begun to regard the growing influence of the Spanish language as a plot against America. And so every congressional session sees some sort of attempt at an English-only bill that would, in the words of the chairwoman of the advocacy group ProEnglish, Rosalie Porter, "preserve English as the common, unifying language of the nation, the states, and of the individual counties, by codifying it into law". While bills of this kind have yet to be passed, there has been a series of analogous legislative actions, including a decree by the Arizona department of education that teachers with "heavy" or "ungrammatical" accents should not teach English classes.

But here's the thing: you can't "preserve" a language without killing it. The reason that English continues to thrive is that there is really no such thing as English at all; there are englishes. Which now number among them the abbreviated and often vowel-less english of the internet. And in this particular english, grammatical accuracy is often cheerfully traded for brevity and convenience. Which tends to be a perfectly acceptable exchange – unless, of course, you're making pedantic points about other people's use of an "official" English.

Not so long ago, we used to be a lot more comfortable with the inherent dynamism of language, adopting a far-less prescriptive approach to its usage. The modal verb "might", for example, had 25 spelling variants in Elizabethan times. Shakespeare even used the form "mought", and when it comes to speaking "good" English, well, he mought to know. Over the last couple of centuries, however, as print capitalism has codified language, we have become a lot more punctilious about our punctuation. And what's more, we have become a lot more smug about it.

But we should watch that smugness. There is no part of language that isn't, in some way, political – and this extends to the satisfying schadenfreude that @YourinAmerica elicits among those who are careful to always put their apostrophes in the appropriate places. Indeed, sometimes it is the people most vocal about linguistic and cultural diversity within society that are also the most close-minded about diversity within language itself – the anti-split infinitive sticklers complacent about the correctness of their grammar without ever questioning what makes this grammar so "correct" in the first place.

Unfortunately, as Kingsley Amis observes, these "people with strong erroneous views about 'correct' English are just the sort of people who consider your application for a job, decide whether you are 'educated' or not, wonder about your general suitability for this and that". And, Amis concludes rhetorically and with biting practicality, "Do you want to be right or do you want to get on?". Because speaking well and writing well isn't just a question of style, it's a question of social mores and social standing. The idea that "If your in America and can't speak English then you shouldn't own a donut shop" is far from being an opinion held only by the illiterate Twitterati. It's engrained in the vocabulary of everyday life.