A trust which runs the Sheffield Springs academy has caused much outrage among defenders of language and the rights of children by requiring teenagers attending the school to use standard English, not slang or text-talk, while in class or in the playground. In the words of Kathy August, the deputy chief executive of the United Learning Trust, "the street stops at the gate".

Reactions, almost all negative, have revealed much about contemporary British attitudes to social mobility. For those worried about nannyism, discouraging slang breaches individual liberty; for lefties, it is part of a snobbish, middle-class plot to homogenise our wonderful, ever-evolving oral culture.

In fact, Kathy August was pointing out a reality which, in saner times, would have been beyond debate. There is, in adult life, a division between the formal and the personal. Language, if one wants to advance in a career, has to be adapted accordingly.

When an application for employment is written as if to a friend – "OMG this job is well interesting" – it is unlikely to lead to an interview. If it does, greeting the panel with a "Yo", "Hey" or "How ya doin'?" will make a less favourable impression than a grey, dutiful "How do you do?"

This bias against the street may seem unfair and old-fashioned, but it is an unavoidable truth that we live in a middle-class world. Most professional life involves impersonating someone more grown-up and better behaved than one actually is.

The fact that preparing secondary school pupils for adult realities has aroused such alarm and opposition shows what a muddle we are in when it comes to class. "It could completely undermine the confidence of the children at the school," Angela Smith, the local MP and a former teacher, has said. "Good luck distinguishing between dialect and 'slang' (IMO a derogatory term used to disparage the language of the young)," wrote an online blogger – pointing up IMO how annoying lazily used text language can be.

This is where moral relativism leads us. A 17-year-old is thought to be undermined by the suggestion that, in some circumstances, he should use language carefully. He feels more relaxed using slang, and so his school is wrong to push him to write or speak any other way – ever.

Adults are being cowardly and dishonest when they encourage teenagers to believe that the world will adapt to them, and the way they speak, rather than the other way round. In a slang-filled world, there will be a narrower choice in employment, and a lot less social mobility.

Landscapes are worth more if painted

It is a bewildering fact that the English landscape tends to be most appreciated when it is on canvas. Dedham Vale, for example, has so far resisted development, not because it is beautiful, but because it has heritage value, having been immortalised by John Constable.

Recently, similar claims have been made for the area around Great Henny in Suffolk, revealed to have been where Thomas Gainsborough painted his "Wooded Landscape with Herdsman Seated" in the middle of the 18th century.

Both these areas are in the path of a row of 196ft pylons which, if the National Grid gets its way, will bring power from offshore turbines in the North Sea into England. The obvious alternative, burying cables, has been resisted by the privatised monopoly on the grounds that it is more expensive.

The fact that the Constable-Gainsborough argument will, quite rightly, be an important part of the planning discussions is revealing. In these debates, what the countryside means to those who live there today is deemed considerably less significant than whether it was painted 200 years ago by a famous artist.

terblacker@aol.com