Emma Thompson's attack on slang: the pedants' battle may be lost

"Sblood, you starveling, you eel-skin, you dried neat's tongue, you bull's pizzle, you stock-fish, you tailor's yard, you sheath, you bow-case, you vile standing tuck..." It's quite a mouthful but, since last month, I have been happily wearing a T-shirt emblazoned with this torrent of abuse from Falstaff in Shakespeare's Henry IV.

The shirt was a birthday present from my teenage daughter, and I hope it marks a turning point in her education: she is learning that, if you want to know how to use good English, you should consult the master, not the sort of people who mark GCSE English papers, and certainly not Emma Thompson.

The actress has just had a pop at the kind of semi-literate teenagers who can't be bovvered to get out of bed, give syntax a miss, and end every sentence with "innit". Their over-dependence on slang infuriates her, she tells the Radio Times. "We have to re-invest in the idea of articulacy as a form of personal freedom and power."

Stirring sentiments, and I have no doubt that parents of teenagers from Exeter to Gateshead will echo them. There is nothing more depressing than the grunts, monosyllables and unfinished sentences of the young.

Once, it was only American teenagers who used the word "like" in every other sentence, to convey the fact that they might be, like, educationally subnormal, but they were also, like, emotionally sensitive in ways they found, like, hard to describe. Now the disease seems almost ineradicable in Britain, too. Eavesdrop on two teenagers talking about their boyfriends/girlfriends and you will be ushered into a bleak, grey world, without nuances of any kind.

As Ed Miliband made his verbally etiolated acceptance speech on Sunday ("I get it... I get it... I get it"), one caught a terrifying glimpse of the politics of the future, in which it will no longer be possible, even for bright people, to advance complex arguments because there is no longer a shared language in which complex arguments can be articulated. The dumbing down of Britain will be complete.

But, unlike Emma Thompson, and other middle-class parents bewildered by the inane patois spoken by their children ("We've sent them to the Cheltenham Ladies' College and they come out talking like Wayne Rooney"), I don't think slang lies at the root of the problem. There is good slang and bad slang, just as there is good music and bad music; and anyone with an ear for language, and a concern for the future of spoken English, needs to make that distinction.

Treating all users of slang as half-wits who need to buck their ideas up if they want the rest of us to take them seriously is like treating everyone with a tattoo, say, as beyond the pale. Language is subtler than that.

The real enemy of communication is not slang, but laziness: the repetition of a word when you know there is a better word. And laziness is not confined to the kind of dopey teenagers who use "wicked" to describe sex, Red Bull, skate-boarding and Lady Gaga, but not Hitler. Dip into any company prospectus, or government report or estate agent's particulars, and you will find a poverty of language that is quite shocking.

The documents are written in polite, intelligible, grammatical English. If you don't know a word, you can look it up in the dictionary – which is not the case with street slang, which is akin to the coded language of a secret society. But they are also bereft of energy, invention, light and shade, humour, irony – all the things that make words sing.

As one bland, inert sentence follows another, you almost wish the authors would resort to slang, just to let their hair down. I hold no brief for Tony Blair, but I suspect the popularity of his memoirs owes something to the fact that he has thrown in the occasional slang expression, such as "blah blah blah" and "get a life", which would have appalled his more po-faced predecessors. The result may not be literature, but it has a conversational ease with which readers can connect.

Creativity is as vital in language as in every other sphere of human existence. There are currently about 300,000 entries in the Oxford English Dictionary; 20 years ago, there were fewer than 220,000. The newcomers did not just barge in unasked. They won inclusion because they plugged a gap – and because someone, somewhere, was clever enough to coin them.

Take a slang word such as "minging", which did not exist when I was a boy. I can't remember how I insulted other boys in the school playground. It was probably something in Latin. I went to that sort of school. But I would have loved to have had "minging" in my arsenal. The word has real onomatopoeic elegance. In fact, it is a far better word than "onomatopoeic", which my daughter and her friends probably think is a sexually transmitted disease.

The very first time I heard the word "minging"– applied by my daughter to one of her teachers – I was captivated. I wanted to know how to conjugate it. Could one use "ming" as a verb? Were "mingy" and "minging" synonymous? Did the word derive from "Ming" Campbell, Liberal Democrat leader at the time? Or was that just an unhappy coincidence? I felt the thrill of the new – just as Shakespeare's audiences must have done, as they heard new words fizzing like firecrackers around the Globe Theatre.

Shakespeare could never have written his plays 300 years later. The sheer verbal exuberance of the Elizabethan era, when words of French, Latin and Anglo-Saxon origin were tossed cheerfully into the same pot, had given way to an age of hyper-correctness, when grammar was king and pedants fulminated against split infinitives and sentences ending in prepositions.

We are not quite as pedantic as the Victorians, but we share some of their vices. We have become obsessed with not making mistakes, at the expense of expressing ourselves. We put too high a price on conformity.

I have never met Emma Thompson, but I suspect she is one of these sticklers for language who go to the lavatory and would cut her tongue out before going to the toilet. It is her privilege, of course, but the tide of fashion is running against her, and pedants insisting on the correctness of "lavatory" will soon seem as passé as restaurants insisting on a jacket and tie.

Chez Davidson, we go to the "dunny", my partner being Australian, and thus versed in Australian slang, a wonderfully mazy tributary of the Queen's English, the by-product of a young, confident country not afraid to experiment with words. Only the other day, I came across the word "fizgig", which you won't hear in London or Birmingham but which in Sydney or Melbourne denotes a police informer. Brilliant.

American urban slang, whether it reaches us via the novels of Elmore Leonard or the films of Quentin Tarantino, is also vigorous and inventive, far more so than English slang, which has been strangled at birth by generations of schoolmasters.

In this country, if you want to find vernacular slang at its best, you need to go to the Celtic fringes – to pubs in Wales, or to the novels of James Kelman and Irvine Welsh, where the characters speak a language that bristles with vitality, unfettered by convention.

Slang alone will never be enough. You need to use a mixture of slang and non-slang expressions if you want to get your message across. But unless you see slang as a potential friend, a chance to be yourself, at ease with your peers, you will just end up as a well-spoken automaton – every sentence you utter immaculate, and not a breath of life in any of them.