The best copywriting uses short, commonly used words in brief, simple sentences.
At university, I would sometimes help friends with their essay writing, partly because I could type and I had a typewriter (remember them?) and partly because I was reasonably good at writing. I never had any problem getting my own ideas down on paper, although the ideas themselves were nothing special, as evidenced by my average degree result. But for many of the people I knew, translating thoughts into written words was a huge challenge.
While taking dictation, I'd often end up providing writing guidance as we went along. When they got bogged down with the phrasing of a particular point, I'd ask them to explain what they meant, and they'd reply with a perfectly clear summary of their thoughts. Then I'd suggest that they simply put what they'd just said into the essay. And they would look at me blankly, or start laughing.
It's tempting to reach for a tone that sounds 'authoritative'
They were falling into the formality trap - the tendency to use jargon, long words and complex sentence construction in writing, out of a sense that the occasion demands it. Under pressure to perform, it's tempting to reach for a tone that sounds 'authoritative' or 'businesslike'. But if you're not careful, you just end up confusing the audience - and perhaps yourself. Of course, it's possible to do this in speech as well, but it's much more of a danger in writing, when we have the opportunity to revise our words over and over if we feel they're not impressive enough.
Do not boil or overheat as this will impair the flavour
They've mostly gone now, but these words once appeared regularly on the soup tins of my youth. The usefulness of this copy depended on the reader understanding the word 'impair'. Personally, I think that's a big ask for the average Fine Fare customer. And why use the obscure 'impair' when you can use the everyday 'spoil'? Presumably because it's less impressive, too conversational. But who cares when there's a risk of the customer ruining the product wrongly through wrong preparation, and never buying it again as a result? If you were offering helpful advice to a friend in the kitchen, you would simply say 'Don't boil the soup, you'll spoil it.'
Please enter the amount required as a multiple of £20
Once, a lady approached me near a cashpoint and asked me why she couldn't withdraw £10. The screen was displaying these words, but the concept of multiples didn't mean a lot to her - quite understandably. No doubt written by a computer engineer, the sentence was perfect on the semantic level but hopeless on the practical level. Messages like this have now been replaced with something more like 'This machine contains only £20 notes', which is essentially what I said to explain the situation.
Often, the use of formal language is simply unthinking. The writer hasn't stopped to consider what the audience needs, and long words come most immediately to mind, so they use them. But it can also be a symptom of a kind of organisational insecurity or defensiveness - there's a need or obligation to communicate, but a psychological incentive to prevent people from understanding. This is one of the key ways in which different types of work (law, printing, web design) are turned into 'professions' - the practitioners develop a private language, or jargon, known only to them. Language is a curtain that stops outsiders seeing how the organisation works and preserves a certain level of mystique. We could trace the practice back to the use of Latin in church services.
I recently received a letter from our local council informing me of a planning application for the 'erection of single-storey self-contained dwelling unit'. I think this means that someone wants to build a ground-floor flat, but I can't be sure. The effect of the language, deliberately or not, is to discourage involvement in the planning process - in theory, a social space, but one closed off by the language that its curators use to deal with the public. The justification would probably be that the definition needs to be precise - but if it becomes opaque in the process, what's the point of precision?