While Finnish is the national language of Finland, about 10% of the people of Finland speak Swedish as their native language. In his 1992 book "Pluricentric Languages" British author Michael Clyne mentions languages that most people are probably aware of as being pluricentric (having more than one form)  like English, Spanish, French and German but he also mentions languages generally not thought of as "pluricentric" too like Korean, Russian and Swedish.

  Clyne mentions that there are some sharp differences between the Swedish of Norland and Skona which had been under Norwegian and Danish control for long periods, and the standard Swedish of central Sweden. He says that the Swedish of Skona is almost unintelligible to someone from central Sweden.

  Clyne focuses a lot on the Swedish of Finland, a colonial variety brought there by Swedish administrators and their families when Finland was still under Swedish rule. He describes it as being somewhat archaic preserving some words no longer used in Sweden and also having some different idioms and pronunciation. He says that there are a few people who would like to classify Finnish-Swedish as a separate languge but he thinks that it is still close enough to Swedish-Swedish to be considered a dialect. He also says that the availability of Swedish television in Finland nowadays is also putting Swedish speakers in Finland in closer contact with the speech of the motherland.  

The story so far: I studied Swedish at a British university and as part of that course spent a year in central Sweden, near Örebro. So my Swedish is that of Svealand - the part of Sweden that was never part of Denmark or Norway. I’ve also spent some time in Helsinki, or Helsingfors to give it its Swedish name. And now..:

For me, the Standard Swedish of Finland is no further away from Swedish Swedish than Scots English is from English English. Yes, it has differences of vocabulary, and the accent is influenced by Finnish intonation - or rather lack of intonation (in fact, sometimes it can take me a while to notice that people are speaking Finland-Swedish not Finnish). But the problems of mutual understanding are really no more than the flat/apartment and boot/trunk ‘problems’ between British and American English. I can’t really see any justification for classifying Finland-Swedish as a separate language.

However, if we talk about Österbotten (Ostrobothnia), on the west coast of Finland, south of Vasa - well, the three dialects there really could qualify as a separate language. They’re pretty archaic, and are supposed to be closer to Icelandic than modern Swedish. Most Finland-Swedes from the Helsinki area would have no more chance of understanding Österbottniska than I would of understanding Jamaican patois. You can get a flavour of it from these examples:

Ein gangg bröut ja eitta beini mett. (Swedish: En gång bröt jag mitt ben) - I broke my leg once.

He e bäst ja kombär igangg, annus kombär int ja heim naagangg! (Det är bäst att jag börjar, annars kommer jag aldrig hem) I’d better get going, or I’ll never get home.

Gets my vote as a different language!

And a few BTWs:

- The southernmost part of Sweden is Skåne, not Skona (although that is a rough approximation of how it’s pronounced). I know the accent from that area is pretty impenetrable, but I’ve no idea how far the dialect is from Rikssvenska.

- According to Ethnologue, the Swedish mother-tongue population is 296,000 out of population of 5.2 million, so that’s around 5-6% rather than 10%.

- A pretty weird usage for "multicentric", don’t you think? Seems to be "(based in more than one area therefore it must) have more than one form"...

Nodders

First of all, a very warm welcome to you, Noddy.

What a great start on this forum! Do return!! Often!!!

In some ways, I’m biased on these questions. I am, according to my late father, a mongrel. He was born in Skåne, that’s the extreme southwest, and my mother in Norrköping, SE of Örebro, so, really, pretty much central to south.

My mother has done some thorough ancestor research, and reaching back to in some cases the early 17th century, there’s only Swedes. There’s a rumour of some Russian fellow far back, but nothing, for example, even remotely looking like a Caucasian. We’re just soo far away from Georgia and its neighbouing countries.

Skånska of course came natural to me, and so does Danish. After all, it’s just a few minutes across the Sound. I tend to regard northerners who claim that they don’t understand Skånska or Danish as just lazy.

My view is that the Swedish in Finland mostly isn’t even a dialect but a variety of Swedish. As has been pointed out, there are vocabulary differences. My favourite is "brushing your teeth", which literally is the same thing in Swedish Swedish, but is "washing your teeth" in Finnish Swedish.

Regarding the Österbotten quotes, I would have no difficulty at all in understanding them, and would probably regard them as examples of a dialect slightly deviating from "official" Swedish. It is, however, possible that I am helped by the fact that one of my uncles hails from the island of Fårö, the islet just north of the island of Gotland in the Baltic. They still use the ancient diphthongs in words like Guthnian (?; Gutniska: their language/dialect/variety) stain, Std. Sw. sten "stone", raud, SS röd "red" and ever so many examples.

At my (over)ripe age of 62, I have still, however, been unable to identify any differences in grammar between, say, Standard Swedish, Skånska, Österbottniska, or Gutniska, and I’ve been interested in languages since at least the age of 4.

For another insteresting (I hope) fact, there’s a variety of Swedish, Älvdalsmål (lit., the patios of the river valley) in the county of Dalarna. Probably for financial reasons, it hasn’t been recognized a a minority language in Sweden under the provisions of the EU, but just as a dialect or such. But it is completely incomprehensible to all other Swedes.

Some minority languages are official in Sweden. Some fulfill the EU provisions, some, in my view, don’t, and some aren’t even brought up for discussion.

Among the officially recognized ones, i.e. Romani chib, Jiddish, Meänkieli, Saami and Finnish, I think that Romani chib (the "Gipsy" language) and Jiddish don’t fulfill the EU requirements on geographical concentration. I can accept Meänkieli (a Swedish-Finnish mix mainly in the border Torneå river valley in the extreme north) as well as Finnish (being concentrated in the north of the county of Värmland, of Selma Lagerlöf fame, as well as in parts of northern Sweden, and to a degree in Stockholm), and I would like recognition of at least two more Saami langages.

Regarding Jiddish, even official reports find it difficult to come up with a number of speakers. (Recording of a person’s religion, ethnicity or home language is illegal in Sweden.) Nowhere, however, the guesses exceed some 6000 people who know Jiddish "well or fairly well" out of our some 8 million people.