Oops! An extra 'they' slipped into that first sentence. Sorry!

I wouldn't call this a plural, and besides (in any case), 'backward(s)' and 'forward(s)' are adverbs not prepositions (although they backward and forward, without an s can also be adjectives).

Etymology Online Dictionary calls them adverbial genitives and dates 'backwards' from the 1510s and 'forwards' from Middle English.

Backwards and forwards are standard in British English, though not in American English (Webster thought 'forwards' a corruption), and the reason you may think they're recent is I assume because you're North American, and certain Britishisms have only begun to appear there quite recently.

'Besides' and 'beside' is a different story, as they are different words with different meanings. 'Beside' (dating from about 1200) is a preposition - 'Come and sit beside me'. Besides, meaning 'in addition to, apart from' can also be a preposition - 'I've got no family besides my parents' or an adverb, meaning 'apart from that, in addition to that' - 'I really can't be bothered to go out tonight, and besides, I've no money'.

@jayles - It's mainstream English for me too, not just for students.

When I first came across "lexis" (in New English File Advanced - where they were really using it instead of "vocabulary") I thought the same as you - I still live in the world of phrasal verbs, as opposed to multi-word verbs! But I've since discovered it really means something more like "vocabulary in context", also known as "lexical chunks" (a bit like collocations, but bigger chunks). The new name isn't just to sound clever, but is intended to put these chunks at the heart a teaching method known as the "the lexical approach", which covers grammar as well as vocab. So I don't think we can just dismiss it out of hand, and in fact I've used it on my blog (with explanation) .

http://www.teachingenglish.org.uk/articles/lexical-approach-1-what-does-lexical-approach-look

And just why, pray, are those of a European background easier to teach? Would it have anything to do with shared language features?

@jayles - I largely agree with you about short words and nominalisations, but I would prefer to say 'use informal, natural, frequently-used words and avoid long-winded, over-formal, relatively unknown or pretentious words'. What I don't want to do is judge words either by their their syllable count or their derivation. There are times when "huge" will do, there are others when I'll want "enormous". There are also times when the judicious use of a nominalisation is rather more efficient than an equivalent verbal phrase.

I do in fact teach my students along these lines, suggesting that they "go to, and take part in, a meeting" rather than "attend, and participate in, a meeting", and often that means favouring Anglo-Saxon over Latin words, but not always. Polish students have a tendency to say "I've observed" for instance (they have a similar verb in Polish) which I find a bit formal, and I often suggest "I've noticed" is more natural (270m Google hits as opposed to 15m for "I've observed"),. But here I'm just replacing one word that has come into English from Latin via French, with another that has travelled the same journey.

But the difference between you and me is I couldn't give a damn (apart, obviously, from interest's sake) where a word has come from as long as it is natural English, does the job and collocates suitably with other words I'm using. And as far as I'm concerned common, frequently used words include "dictionary" and "vocabulary", whereas "wordbook" and "wordstock" (red-lined here) fall into the other category.

What's more, I can't agree with the approximations of synonyms and collocations that are being discussed on the Anglish page. For example, "outlandish" was suggested instead of my use of "preposterous". Well, I might think that the whole Anglish idea is somewhat outlandish ("strange or extremely unusual"), but I wouldn't insult you and your fellow Anglishers by describing it as "preposterous" ("unusual in a silly or shocking way"). Definitions from OALD. "Ongoing" was said be a suitable substitute for "continuous", sometimes yes, sometimes no:

http://books.google.com/ngrams/graph?content=continuous+noise%2Congoing+noise&year_start=1800&year_end=2000&corpus=15&smoothing=3&share="

I'm just not prepared to be bound by any rules other than those of natural idiomatic English shaped by custom, whether these rules come from prescriptivists,language purists or the silly ideas that come out of certain schools of English, such as avoiding the passive and singular they, or always using "that" in restrictive relative clauses.

I'll finish by quoting David Crystal, probably the leading expert on British English:

"There is a curious myth widespread in the world: many people believe that their language can somehow be 'pure' ... and that anything interfering with this imagined purity (especially words borrowed from other languages) is a corrupting influence ... . In the case of English, there is a special irony, for its vocabulary has never been purely Anglo-Saxon - not even in the Anglo-Saxon period". He goes on to explain how there had been four centuries of interchange between Germanic and Romanic people before the Anglo-Saxons even arrived in Britain, with many Roman cohorts consisting of men from Germanic tribes.

Or there's James D Nicoll's well-known analogy - "The problem with defending the purity of the English language is that English is about as pure as a cribhouse whore. We don't just borrow words; on occasion, English has pursued other languages down alleyways to beat them unconscious and riffle [sic] their pockets for new vocabulary"

I've read somewhere that English has borrowed words from over 300 languages. English is by its nature a borrower. This is one of the very things that differentiates it from other languages. And makes it so glorious.

douglas.bryant, porsche and JoshK have more or less said it all. I don't know about American English, but it's quite common in British English, and it's never occurred to me that it could be anything but "I". Simply checking with a dictionary confirms this. Oxford Dictionary Online lists the idiom as "(I) don't mind if I do", as does the Free Dictionary.

http://idioms.thefreedictionary.com/don%27t+mind+if+I+do.

@AnWulf - Let's take them one by one.

"That my scorn of Lucky Bill upsets you doesn't amaze me" - I have no doubts about the tyranny of William I. What I have doubts about is how relevant events that took place over 900 years ago are to modern English. Or the way in which you connect modern (especially British) spelling ( - colour, realise etc) and other language points to those events. Should we Scots still be hating the English for much more recent events?

I also find that the Anglo-Saxons, (and Norsemen, or in fact anyone vaguely "teutonic") who also started off as invaders or raiders, seem to get a very easy ride in your view. Even Anglo-Saxon scribes relate how brutally certain Anglo-Saxons treated Celtic Britons on occasion, but no, only the Normans can be ever be criticised in your book. Sorry, but I just don't see history in that sort of black and white perspective.

Admittedly, under the Normans, many Anglo-Saxons had to learn French words to carry on business, appear in court etc. But as I understand it, there were two periods of French influence, first Norman or Anglo-French, and later Parisian French, some time after John Lackland had lost Normandy and by which time the descendants of the Norman barons had started to speak English.

And as I understand it (again), the largest tranche of French words entered English in the 13th and 14th centuries (from Parisian, not Norman, French). These were not forced on anyone, but willingly adopted by the English educated classes as Paris had become the capital of European culture, and was widely admired as such. Basically, French was seen as "cool".

"as well as put a Frenchman as head of the church in England who at once put a stop to putting the Bible into English" - As far as I'm aware, the medieval Catholic Church, especially under Innocent III, didn't want the common people in any country reading the bible in the vernacular, whether it be in England, France or Germany. This is why Wycliffe had so much trouble (around the end of the 14th century, long after English had become the dominant language) and why Luther thought it so important to make a translation into German. I doubt this has much to do do with French vs Anglo-Saxon, but to do with church politicy at the time; there doesn't seem to have been a French translation before 1530, for example.

"English does not hav two roots" - I obviously accept that the grammar of English has its roots in Anglo-Saxon and is a Germanic language. And I quite agree with you about those grammarians who tried to fit English grammar into a Latin framework. However, the contribution of French in terms of vocabulary has been so enormous, that I think it should be credited. I personally like having a language that looks in two directions, to its Germanic roots and to its French and even Latin influences. This is from the British Library website:

"The English language is a vast flea market of words, handed down, borrowed or created over more than 2000 years. And it is still expanding, changing and trading. Our language is not purely English at all - it is a ragbag of diverse words that have come to our island from all around the world. Words enter the language in all sorts of ways: with invaders, migrants, tradesmen; in stories, artworks, technologies and scientific concepts; with those who hold power, and those who try to overthrow the powerful."

And that's why I love it - all of it. I'm all for expressing my identity through language, but I dislike any type of cultural purism.

"You may "revel" in 'sesquipedalian' words like obequitate, perambulation, circumjacent, prognosticate " - Now you're just being plain silly! Never heard of two of them, never use another, and can't remember ever using "prognosticate", but may have once or twice. But it does remind me of this sign for guests, purportedly from an Austrian hotel - "Not to perambulate the corridors in the hours of repose in the boots of ascension"

I notice that you don't mention such dastardly "inkhorn-terms" as "agile, education, harass, scientific, strenuous". (Anyone can play the word game - the truth is that many Latin words adopted were not "sesquipedalian" at all). I wonder why hardly any of the "English" equivalents proposed at the time have survived.

Lastly, I wish you'd allow people to disagree with you without calling us names such as "Latin lovers", or suggesting that our "mindset" is somehow at fault (i.e. we've been conditioned), or that "two few people know" what you know. Are we not allowed to have minds of our own without being condescended to in this way? Just because most of us judge each word we use on its own merits and don't worry unduly where it came from five hundred years or so ago. And just because some of us prefer to look at our language (and history) as objectively as we can, and not from one particular (to my mind somewhat slanted and rather bile-laden) viewpoint. :)

Peace breaks out all round :))

@Loumi - As you're in Canada, I'm not surprised you haven't heard it, as this seems to be a purely British English (including parts of the Commonwealth) thing, and yes, a minority use (though that minority is quite substantial, and as far as I can assess, well educated).

@Hairy Scot - yes it's certainly used in business, but even more in politics and also in academic writing, I think. As I said before, I think it tends to be used more for important and weighty decisions.

Some interesting data from Ngram (for published books). Neither seem to have been used much before 1900, but while in the US, "make a decision" had taken an early lead, in Britain, there wasn't much in it before then. There are plenty of examples of "took the decision" from the 19th century in Google books (mainly British).

https://www.google.com/search?q=%22took%20the%20decision%22&tbs=bks:1,cdr:1,cd_min:1789,cd_max:1871&lr=lang_en

From about 1920, use of both increased, with the ratio seeming fairly constant at 3:1 in British books. (red and blue for US books, green and orange for British books.)

1780 - 1900 http://books.google.com/ngrams/graph?content=took+the+decision%3Aeng_us_2012%2Cmade+the+decision%3Aeng_us_2012%2Ctook+the+decision%3Aeng_gb_2012%2Cmade+the+decision%3Aeng_gb_2012&year_start=1780&year_end=1900&corpus=15&smoothing=3&share=

1900-2008 http://books.google.com/ngrams/graph?content=took+the+decision%3Aeng_us_2012%2Cmade+the+decision%3Aeng_us_2012%2Ctook+the+decision%3Aeng_gb_2012%2Cmade+the+decision%3Aeng_gb_2012&year_start=1900&year_end=2008&corpus=15&smoothing=3&share=

But the surprising thing is a huge peak for "took the decision" in American English around 1776. That's why I had to start it in 1780, to avoid distortion. Disappointingly, I can find no reason for this peak.

@Loumi- " Personally, I would never rely on newspaper articles wherein numerous grammatical errors can be found."

Well, instances of "take" are certainly quite numerous. Google site searches today:

The Guardian - "made the decision" - 57,800 - "took the decision" - 16,000 (28% take).
The Independent - 7830 to 3060 - (39% take)
The Daily Telegraph - 11,000 to 5990 (54% take)

These percentages, found in the quality press, sound to me to be rather high simply to be "grammatical errors" (if using the "wrong" verb is indeed a grammatical error).

And does the same go for dictionaries?

http://oald8.oxfordlearnersdictionaries.com/dictionary/decision
http://www.macmillandictionary.com/dictionary/british/decision
http://www.ldoceonline.com/dictionary/decision

And language used in parliamentary reports and academic works:

https://www.google.com/search?q=%22took%20the%20decision%22&tbs=bks:1&lr=lang_en

The onus really is on the doubters to prove that "take a decision" (in British English) is somehow wrong.

This graph would suggest that the use of "reference" as a verb has increased quite dramatically since about 1960, and that although more common in the US, has seen a similar, if smaller, increase in the UK. But the good news for those who don't like it is that the increase seems to be levelling out in both branches of English.

http://books.google.com/ngrams/graph?content=referenced%3Aeng_us_2012%2Creferenced%3Aeng_gb_2012&year_start=1950&year_end=2000&corpus=15&smoothing=3&share=

@Damian C - I wasn't making any judgements either way, simply observing. Although I certainly agree with you about my last BNC example, which I'm not sure was even grammatical. My interest in the US government document also had to do with its age. This usage isn't necessarily as new as some people would think.