A grad student from the US writes to ask if there have been other attempts to provide a simplified English apart from Ogden & Richards' Basic English and Quirk's Nuclear English. She wonders why these attempts never prospered. Is it, she asks, because linguistic simplification is impossible to achieve, as an end in itself (as opposed to the simplifications introduced when teaching English as a foreign language, as a stage towards students achieving command of the full language)?
There certainly have been other attempts to provide a simplified English for special purposes. One was devised for the European Association of Aerospace Industries (AECMA), for simplifying maintenance manuals. The Voice of America has a 'Special English' project, with restricted vocabulary and simplified grammar, which has been going since 1959. And there have been several constructed languages based on English which aim to facilitate international communication, such as Seaspeak, Airspeak, and Policespeak.
I suppose you might include under this heading the kinds of simplification introduced by the UK's Plain English Society (or the equivalent in other countries) in their campaigns to increase everyday intelligibility. These are an end in themselves, and on the whole very successful too. But they had to fight to get their proposals adopted, and the battle against gobbledegook is by no means over. Plain English campaigns are only a partial simplification, though, being focused for the most part on formal written English intended for the general public.
An arbitrary simplification of the entire language is unachievable, in my view. All artificial or constructed languages come up against the same problem: how to bridge the gap between the simplified form and the reality of English as it is spoken and written (and, now, used on the internet) in its full range of unsimplified varieties? One needs to preserve continuity (with the non-simplified language) and to provide motivation. The logical arguments are all on the side of those who argue for a simplified English spelling, for example, but the pragmatic arguments are not - and pragmatics always wins. The only simplified spelling movement to have succeeded was Webster's, in America, and that was for a special set of reasons (coinciding with US independence). There have been dozens of proposals for simplified spelling since, and none have made much headway. Progress would be even more difficult to achieve if proposals were made to simplify grammar and vocabulary. The usage brigades would be on the streets fighting to defend the language's expressive richness.
Simplification is actually complicated. It sounds easy, for example, to reduce vocabulary to a core set of words. But as soon as you do that, if you want to maintain your expressive power, you have to increase sentence length. Look at the way the Longman Dictionary of Contemporay English handles its defining vocabulary of 2000 words. All the entries restrict themselves to those words, but as a result some of the definitions get quite long. The whole point of 'long' words is that they compress into a single unit what it often takes many words to say.
A distinction has to be made between artificial and natural simplification. I don't think artificial proposals are likely to succeed, outside of special circumstances (such as Seaspeak), though they might achieve a fashionable status for a while. But natural processes of simplification are certainly possible - and visible today on the Internet. If one looks at the kind of language used in chatrooms, instant messaging, texting, and other genres of language where the technology or the nature of the interaction requires short and speedy responses, then we find shorter sentences, reduced vocabulary, and simplified spelling, capitalization, and punctuation. I give some statistics and illustrations in my Language and the Internet - the second edition in 2005 includes instant messaging and blogging, which weren't around when the first edition appeared. It's too early to say whether any of these simplifications will have a long-term impact on language; they remain special varieties at present. But when you type rubarb, for example, into Google and you get 85,000 hits, it makes you wonder. Maybe English spelling will simplify, in the long term, as a result of Googlonian democracy.