‘A language is a dialect with an army and navy.’
It is not recorded who first said this. An American came out with it during discussions in the 1940s of whether Yiddish was a language or merely a dialect of German.
Merely is the important word here: the difference between the two seems often to be one of status. Danes and Norwegians, for example, understand one another, but because they are separate countries, they are assumed to have separate languages, although a linguistics expert might consider both to be dialects of a single language, with perhaps Swedish as well.
In England, dialects can cause misunderstandings. When the railways started having unguarded level crossings in the 1970s, there was a standard notice for the country:
Do not cross while red light is flashing.
After some hair-raising incidents in remoter parts of Yorkshire, someone remembered that in the Yorkshire dialect, while was still used to mean until (as it sometimes does in Shakespeare): and so the wording was changed.
If you hear in Lancashire someone asking about a new baby, “Who does she favour?” that means, “Who does she look like?” Again, this kind of usage can be found in Shakespeare.
What about Scots, the language of lowland Scotland, so like English and so unlike?
‘Right sair she grat,* an wet her cheeks…‘ (Robert Burns, Blyth Will and Bessie’s Wedding)
Scots is recognised as a language by UNESCO. It was, of course, the court language of the Stuarts—but they did not import it when they came to the throne of England. Scots is preserved beautifully by a number of poets, including Robert Burns, and earlier, William Dunbar (recommended).
To return to the remark at the beginning: the unnamed Jewish American who said these words may have been a classicist. Attic Greek (see last post), started as a local dialect, but became, several hundred years later, the Greek language in its standard form; and Latin, which started life as a local dialect of Italian, not only became the language but gave its name to it.
We may add that in both cases it was not just an army and navy: both dialects produced a literature that was substantial and survived.
* Very bitterly she wept…