TWO years ago, a short post on the Johnson blog, called “What is the Chinese language?”, became one of the most commented pieces in the history of Economist.com. Classifying languages is a hot topic, because linguistic and social facts can be hard to disentangle. Last week, we returned to the topic with a piece called “How a dialect differs from a language”, explaining that mutual intelligibility is the most important criterion for language experts. On these grounds, for example, Cantonese and Mandarin are two languages, not two dialects of a single language called Chinese.Once again, many passionate objections appeared in the comments. One is that speakers of different dialects of English can struggle to understand each other too. Does that make an Irish brogue and an Appalachian twang “languages”? No. But why not? The best answer is that they are very obviously modifications on a standard framework. Through education, most people learn to avoid dialect features and move along a continuum towards a well-known standard. The national standards (General American, RP in Britain and so on) are nearly 100% mutually intelligible. And even a conscious attempt to avoid dialect features is not usually necessary. Johnson’s father came from Macon, Georgia, and spoke a heavily southern American English. He was not an experienced international traveller, but when we visited rural western Ireland, any head-scratching was brief: he was understood by, and understood, everyone.

Simply put, it would be a struggle to find any two “English” speakers around the world who truly cannot converse. Scenes like the famous subtitled “jive” from Airplane! are funny precisely because they don’t happen in real life. Now some varieties of “English” are so opaque to most English-speakers that they are considered languages: New Guinea’s Tok Pisin, Jamaica’s Creole and America’s Gullah are just a few. Some, like Jamaican Creole (“Patois”), run on a continuum, from a mere accent to fully unintelligible to outsiders. But accent, a few local words and a tiny few grammar differences (like you/y’all/youse), do not hinder comprehension enough to make Kentuckyan or Brooklynese “languages”.

What about the Chinese case? A Cantonese-speaker cannot simply minimise a few Cantonese features of his speech, moving smoothly towards a standard, to be understood by someone from Beijing. A list of ordinary Cantonese words shows stark differences from standard Mandarin, not just tomayto, tomahto stuff. They include “this” (Cantonese ni, Mandrin zhe), “that” (go/na), “here” (nidouh/zher), “is” (haih/shi), “no/not” (mh/bu), “now” (yihga/xianzai) and “home” (ukkei/jia), and many more. Nor are these occasional words like lift v elevator. “This”, “that”, “here”, “no” and “now” are the very guts of a language. So unlike "jive" into English, Cantonese movies really are subtitled for a wider Chinese audience.

But none of this discussion should ignore the fact that Han Chinese do often consider themselves to be speaking the same language with local variety, not dozens of languages. To say they are simply wrong is not helpful. A language is also a social construct, an “imagined community”. These constructs or communities should not be dismissed as fantasy. And so some linguists, especially sociolinguists, take into account what people call their language, how they talk about it, and whether they share a literature.

To illustrate, one commenter on our “Explains” article recommended the Wikipedia article which lays out the concept of an Ausbausprache, roughly a “constructed” or “built-out” language. This is usually a vehicle for national identity, even if it has mutually intelligible neighbours. “Bokmål” Norwegian is considered a traditional example. At a recent Copenhagen press conference hosted by Danske Bank, the Norwegian chief executive joked “I hope you understand my dialect of Danish” before addressing the reporters in Norwegian. They asked their questions in Danish and he replied in Norwegian again. In the jargon, his Norwegian might not be an Abstandsprache—a language by virtue of its distance (Abstand) from Danish. But it is an Ausbausprache, an official standard and a sociolinguistic reality that Norwegians take seriously as a language. It would be blinkered, not to mention rude, to say that they are simply deluding themselves.

Marginal cases abound. Local versions of Italian and German are called everything from “accent” to “dialect” to “language”, and some are mutually unintelligible. Serbs, Croats, Bosnians and Montenegrins are busily creating Ausbausprachen out of what was once a single Serbo-Croatian. Some commenters sarcastically wondered aloud whether Spanish and Portuguese should be considered a single language. We might well add: what about Portuguese and Galician? Dutch and Afrikaans? Farsi and Dari? Hindi and Urdu? Mutual intelligibility may be the go-to standard, but where that isn’t decisive, even linguists, while they care mostly about pronunciation, vocabulary and grammar, consider non-linguistic factors like self-perception.

The fact is that most people aren’t linguists, and social reality is important. My favourite comment on the whole debate was this one, in relation to the question of whether Chinese is one language with dialects or a family made up of languages:

Both answers are correct. They're coming from two different perspectives that use different criteria as to what qualifies as being a language. It's like when you get biologists arguing with chefs about what the difference between a fruit and a vegetable REALLY is.

Try offering your child “a piece of fruit”, and then when he accepts, handing him a chili pepper. The specialists’ definition is not the only one that matters, as any good specialist knows.