The first is the tremendous diversity of accent and style and register and dialect within English itself, as spoken by native speakers (thus excluding the diversity of foreign accents / variants / dialects in English). Even though there are far more native speakers of English in the US spread out over a far vaster area, the actual variations are minimal compared to the incredible differences that occur in the UK. Why this is the case, I don't know, aside from a possibly doubtful factoid I read somewhere sometime that a language shows maximal diversity within the geographic region of its birth. It may be because migrants tend to retain the language of their youth and attempt to artificially preserve it in some manner; I do know for a fact that my Tamil is more akin to the Tamil of my grandparents' generation than it is to the Tamil spoken by the kids of my generation who've grown up in the fertile Kaveri delta.
The second is the palimpsestic layering of languages, where the successively fainter traces of successively older languages can be found in just about everything, most obviously in toponymy and lexis. North America too would have enjoyed this when Columbus landed on its shores, and Native American influences can certainly be seen on American toponymy, but the near-total destruction of the Native American populations and the extent to which the mainstream European settlements in the continent set themselves apart from the Native Americans meant that the linguistic continuity still visible today in Britain was, alas, irreparably ruptured in North America.
I don't mean to say that these modes of diversity are somehow exclusive to Britain or particularly denied to the US; it is merely that they are much more visible to me in Britain than they are in the US.
Accents or dialects?
Given the extraordinary globalization of English, it's probably accurate to say that everybody, even native speakers, speaks English with an "accent". It's possible to identify people's nationalities by their accents, and with some practice to dive even deeper into their backgrounds; there is a distinctive Bostonian accent just as there is a distinctive Keralite accent, and I'm sure Sydney speaks a different variety of Strine than Perth does. But within the UK, the diversity is absolutely staggering. A native of the UK, born and bred in the country, will be able to place someone within a particular county, possibly even within a particular town in that county, based on shifts in accent or vocabulary that are entirely imperceptible to me. In the West Midlands, the "Brummie" Birmingham accent is supposedly different from the accent of the Black Country, just a few miles to the northwest—both are equally incomprehensible to me though, so I couldn't tell you what the differences are. Black Country English supposedly preserves some very archaic features of Early Modern English that have otherwise been lost in other forms; all I can say is I'm glad we don't all pronounce "horse" to rhyme with "arse"!
Sometimes these differences are so sharp that the natives are speaking a different language, for all intents and purposes. Now naturally the native speakers of these languages are unlikely claim that they speak a language different from English, which makes it difficult for us to continue calling them "languages"; I suppose we then have to call the more extreme accents "dialects". After all, "a language is a dialect with an army and a navy," to cite the quotation often, but wrongly, attributed to the linguist Max Weinreich. But the fact still remains that accents and dialects and languages are artificial, frequently political, distinctions that are externally imposed on what is in purely linguistic terms a spectrum.
This was nowhere clearer to me than in Scotland, where the English (spoken by native Scotsmen) varies from "standard" BBC English, to the presence of a trilled 'r' and hard 'ch' and and a few peculiar words like "bonnie" and "wee", to a very pronounced "Scottish" accent, to a language that doesn't really seem like English anymore. This is of course the Scots language, a surviving branch of Middle English, the language of Robert Burns, distinct in many major points of grammar and vocabulary from "standard" English. Scots is different from Scottish English (which is grammatically mostly standard English but whose pronunciation is influenced by Scots), Scottish Gaelic (the Celtic language brought to Britain from Ireland which is very close to Irish Gaelic), and from Highland English (English heavily influenced both by Scots and by Scottish Gaelic). This complex linguistic picture was presented to us by our tour guide, a kilted Scotsman with a barely noticeable trilled 'r' who nevertheless could speak "braid Scots" when needed, and who possessed some knowledge of Scottish Gaelic. This last point is important to note, for Scottish Gaelic, like Irish Gaelic and unlike Welsh, is rapidly fading away.
A Brief History of Languages
The linguistic history of the British Isles is incredibly fascinating, and I've been trying to read up a bit more about it (on Wikipedia, of course!). And the picture I've gleaned from a quick skim is incredible. Excluding the pre-Indo-European languages of Britain (about which we know regrettably little), the major language families to have existed here include the Celtic, the Norse, the Germanic, and the Romance: four huge language families on one little island!
We know almost nothing about the pre-Celtic languages spoken on the isles, except that they must have existed: the great Neolithic sites like Stonehenge predate the coming of the Celtic languages, who were probably the first Indo-European-speaking peoples to cross the English channel into the British Isles. But about the Celtic languages we know much more. We know, for instance, that there were a number of Celtic languages spoken in modern France and Spain, giving rise to the names Gaul and Gallic and Galicia, and that these languages had long been in contact with the Italic branch of the great Indo-European family (the branch that gives rise to Latin and then to the modern Romance languages). Some of these people push off from modern Galicia and Normandy and land in the British Isles, bringing with them not one, but two distinct flavors of Celtic tongues.
This is a good place to note that the migration of languages is not necessarily connected with the migration of peoples or with violence. A very small number of people may migrate to a new land and quickly become indistinguishable by blood from the surrounding population, and yet their language may come to be adopted even by the majority surrounding them, possibly with great phonological and morphological changes, possibly almost unchanged. We don't know how many Celtic-speaking people came over, nor do we know if their coming was bloody or peaceful. We don't even know how many languages these people spoke when they first landed in Britain; all we know is that there are two distinct Celtic language families present in the isles.
In Ireland, the Goidelic family flourishes, spoken by the early Gaels, while in Britain it's the Brythonic languages. The former gives rise to modern Irish and Scottish Gaelic; the latter to modern Welsh, Cornish, and Breton. One small wrinkle here is with the Pictish language, possibly but not definitely a Brythonic Celtic language. Spoken north of the Firth of Forth (near modern Edinburgh), the Pictish language was spoken by (duh) the Picts, after one of whose tribes the Romans named the region Caledonia. Now neither language family stays put, of course. Some Brythonic speakers resettle in mainland Europe, surviving till today in Brittany. Some Gaels from northern Ireland invade western Caledonia to establish the kingdom of Dál Riata, thus introducing a Goidelic language into the Isle of Man and into Britain. (One fascinating tidbit: today in Scotland, the word "Gaelic" is pronounced "Gallic", but in Ireland it's "Gaylic".) The Romans called the Gaelic population of Dál Riata the Scotti, whence the name "Scotland". The Scotti and the Picts alternate between making war and making love, until the two kingdoms are united to create a single Scottish kingdom (alas, with the loss of the Pictish tongue).
The Celtic languages have already existed in contact with the Italic languages during their co-existence on mainland Europe, but when the Romans invade Britain, Latin exerts a massive influence on the languages, possibly more on the Brythonic than the Goidelic. The Romans also add an extra element of linguistic diversity: since a substantial portion of their army is composed of non-Italian auxiliaries, some of their languages (Saxon for sure) are also brought to the Isles at this early point. Of course, the Germanic languages come in much greater numbers later.
Around the time the Romans start quitting Britain, major changes are afoot on the mainland. Turkic-speaking Hunnic tribes are pouring in from Eurasia, squeezing all the other existing European tribes into ever-shrinking territories. Small wonder then, that some of the Germanic groups—the Angles, the Saxons, and the like—set sail for the shores of fair Albion. Some of these settlements were probably peaceful while others were quite violent; it's funny then that, in a sense, a skirmish between ethnic Anglo-Saxons and ethnic Brythonic-speaking Celts is a fight between the English and the British! (I claim poetic license to slightly misuse the words for humorous effect.)
Other, more northerly Germanic tribes also begin to raid the coasts of Britain and Ireland—the wild Vikings, speakers of Norse languages (whose ancestor, Old Norse, is descended from Proto-Germanic just as these other languages are). In parts of Scotland, the two groups actually begin to co-exist as the so-called Norse-Gaels, and I wonder what sort of curious Celtic / Norse mixture they must have spoken! Curious fact: the words "Loch Ness" and "Inverness" are a mixture of Gaelic and Norse: "loch" is of course Scottish Gaelic for "lake", while "inver" is the anglicized version of Scottish Gaelic "inbhir", meaning "confluence", and "ness" is the anglicized Norse "nis", meaning "large body of water".
Old English, at this point essentially just a collection of Anglo-Saxon dialects, was thus a very Germanic language that was nevertheless heavily influenced by Latin (thanks to the educated monks), by the Old Norse-speaking invaders (a different flavor of Germanic), and by the pre-existing Celtic languages. A number of Old English words still survive today in Modern English; we tend to think of these words as somehow being shorter, crisper, and more direct. Reading some Old English poetry in the original gives us a sense of how near we are to that tongue, and yet how far.
But of course, there is yet another hugely important linguistic influence that shapes Anglo-Saxon into Modern English, and that is of course the linguistic impact of the Normans. The language spoken by the Norman invaders and later rulers of Britain was (surprise surprise) Old Norman, a dialect of Old French. As with anything else, such naming of languages shows the difficulties we face in accurately labeling and classifying a complex, fluid linguistic situation. To be more precise, the various languages spoken in the region of modern France around this time are collectively called Old French and can broadly be grouped into two families based on the word used for "yes". The more northerly group, into which both Old Norman and modern "standard" French fall, is the so-called langues d'oïl; the southerly languages, including old and modern Provençal, are the langues d'oc. (Bear with me, jay nuh parlay pah luh fronsay!)
The impact of Old Norman and its descendant Anglo-French on English was profound, to put it mildly.A gigantic amount of Latinate / Romance vocabulary was imported wholesale into English, changing the language's style and expression forever. The reason kids who study Latin do better on the SATs is because the Normans invaded and ruled Britain and transformed the language; otherwise we'd be pointing to German as a model worthy of emulation.
The firststuffs have their being as motes called unclefts. These are mighty small: one seedweight of waterstuff holds a tale of them like unto two followed by twenty-two naughts. Most unclefts link together to make what are called bulkbits. Thus the waterstuff bulkbit bestands of two waterstuff unclefts, the sourstuff bulkbit of two sourstuff unclefts, and so on. (Some kinds, such as sunstuff, keep alone; others, such as iron, cling together in chills when in the fast standing; and there are yet more yokeways.) When unlike unclefts link in a bulkbit, they make bindings. Thus, water is a binding of two waterstuff unclefts with one sourstuff uncleft, while a bulkbit of one of the forestuffs making up flesh may have a thousand or more unclefts of these two firststuffs together with coalstuff and chokestuff.
The rest of the essay is available here. It's a fascinating exercise to try to piece together what Anderson means, and to try to explain his reasons for his coinages (in most cases, from the Latin or Greek etymology of the word replaced; in some cases from the German equivalent). Wikipedia has a fully hyperlinked version of the passage, which should aid in completely deciphering it.
