In terms of their grammars – their syntax and phonology - Languages do not form a continuum. There are structural discontinuities which mean that when you learn a foreign language, often enough you have to learn more than a new vocabulary. Sometimes the structures are radically different: Finnish is not a bit like the other Scandinavian languages. In fact, from a structural point of view, it is most like Hungarian. (So in language typologies, these two monstrously difficult languages are grouped together as Finno-Ugric).
But the Scandinavian languages (Danish, Norwegian, Swedish) are more different now than they once were. There is still a high level of mutual inter-intelligibility – a Swedish speaker can understand a Danish speaker, even though they cannot speak Danish, and the Danish speaker can understand the Swedish speaker.
But as part of nation-building efforts, the three languages have been developed away from their common core. This has both advantages and disadvantages. On the plus side, standardisation - achieved through control over what is taught in schools and then through such things as sub-editorial policies in publishing houses - does result in more efficient communication. It takes less time to understand what someone else is saying, or make sense of what someone else has written , the closer they are to you in terms of syntax, phonology, vocabulary and spelling. And there is less chance of misunderstanding.
The disadvantage is that as you move a language away from its core or from another language, you eventually reach a point where you can’t understand your near neighbours and vice versa, they can’t understand you. To communicate, at least one of you has to learn what has now become a Foreign Language. Doh!
Nation-building and nationalism more generally have positive features. If you think of yourself as Czech and are proud of that fact, then that provides quite a good basis for simple forms of civic consciousness. You’re Czech and proud of it and that’s one reason you don’t drop litter in the street.
But nationalisms generally lead to excesses of one kind or another. Some are distinctly unpleasant, such as hatred of foreigners. Others are more simply tiresome. Language policies are often in this category.
Everyone knows that the French, who maintain a very strong sense of national identity, have an absurd relation to their language. They don’t want it to change. When I was first in France in 1971, I had a conversation with a couple who admired de Gaulle not least because he knew how to use the pluperfect of the subjunctive in his speeches. But to demand that a language does not change is an impossible demand, a King Canute kind of demand.
And the French don’t want Foreign Words contaminating their language. So they want you to say site-web and not website because it’s more French (just like Pages Jaunes for Yellow Pages). The French don’t want a coffee - coloured language.
Nor do the Russians and Ukrainians who insist on quite minor differences when, from the point of view of communication, it would be very useful to go with the flow of language mixing and what linguists call Free Variation – which means, roughly, that one form is reckoned as good as another (think of Hallo and Hello in written English).
Rather than tolerate Free Variation, Russians and Ukrainians are very insistent on staking their claims to difference. In Cyrillic, the spelling is the same, but the town which Russians would call Gomel has to be transliterated for a Ukrainian as Homel . Likewise, for Russians it’s Sevastopol but for Ukrainians it’s Sevastopil. The sensible thing might be to accept free variation between the two, as one does for Hallo / Hello. (For the Tatars, who also live there, it’s Aqmescid , so they can’t get in on this particular bit of mixing).
Sevastopol / Sevastopil feels a bit like the differences between the Russian Orthodox Church and Old Believers, which focus on ritual – Is the thumb involved in making the sign of the Cross? and so on (go to Wikipedia on “Old Believers” if you enjoy this kind of thing).
Coffee-coloured languages mean that more people can join in a game – business, sport, tourism – whereas linguistic nationalism is designed to exclude. Where absolute precision is required, then it’s often necessary to use a special language which might be Latin (think of the development of theology or medicine) or nowadays is more likely to be English (think of air traffic control).
But most of the time, we should accept and enjoy coffee-coloured languages.
Well, after all that, I need an espresso or at least a latte.