(I am indebted to Ken Caviness for preparing this material. Quotations have been edited.)
Interestingly, while English was spoken by about 10 % of the world's population in 1900, and by about 11 % in 1950, it is today spoken by about 8.5-9 %. The corollary is that, for better than 90 % of the world's population, it is not the de facto means of international communication.
English is a very difficult language to learn unless you've been immersed in it since birth. English spelling is said to be more difficult than any other language except Gaelic. English grammar, although it may be fairly simple, is riddled with exceptions. Verbs are very often irregular. Many people just aren't going to devote several years of effort to learn it!
English has gained its present stature because of the current economic and political power of English-speaking countries. In the past, every super-power has briefly seen its native tongue used internationally: France, Spain, Portugal, the Roman empire. In fact, one of the main reasons why Esperanto was never adopted by the League of Nations was that France blocked efforts to adopt it. At the time, French was "the international language", and France expected it to stay that way forever. They were proven wrong within twenty years.
Although many people all over the world study English and often think they speak it well, the number of people who can participate in a non-trivial conversation in English is very small outside English-speaking countries. Knowing English may be sufficient to survive as a tourist in many places, but not for more.
One Chinese Esperanto speaker described Esperanto as a linguistic handshake. When two people shake hands they both reach out halfway. When two people speak Esperanto they have both made the effort to learn a relatively easy, neutral language instead of one person making the huge effort to learn the other person's difficult national language and the other person making no effort at all except to correct his/her interlocutor's errors.
Yes, actually it is. You see, it's been used in all conceivable circumstances for over 100 years. Whatever you have to say, you can say it in Esperanto.
It's said that Umberto Eco, before he started supporting Esperanto, once said in class that Esperanto isn't a real language, "because you can't make love in Esperanto". A girl later wrote to him and said, with some embarrassment, "I'm sorry, Professor, but it is possible to make love in Esperanto. I've done it."
Personally, I don't believe it. I mean, I don't believe she actually said so. Oh, forget it. ;-)
(1) Esperanto is intended to be your second language, so it remains relatively intact: people primarily create slang, idioms, etc., in their native language.
(2) Esperanto is intended for cross-cultural use, therefore use of too many colloquialisms, etc., jeopardizes your chances of being understood (which is presumably your intention). This acts as a stabilizing influence on the language.
Regional dialects appear when people communicate mostly with their geographical neighbours and rarely with people from further away. Dialects tend to disappear when long-range communication dominates (as can be observed in many parts of the world after the introduction of radio and television). There is also the not insignificant observation that Esperanto has not formed any dialects in its more than one hundred years of existence.
Duncan C Thomson:
Esperanto has just as much literature (original, not just translated) as any other language of a similar number of speakers. Just because you haven't heard of it doesn't mean it doesn't exist.
Have you heard of Auld, Szathmari, Kalocsay? Galloway, Gray, Kelman? None of them, probably, but you would probably not be as quick to claim that Scotland did not have a literary culture.
[Several tens of thousands of books have been published in Esperanto; the library of the British Esperanto Association has 30 000 volumes. There are about 100 periodicals of some importance, plus countless local bulletins and newsletters. At one point there was even a daily newspaper in Esperanto! I have no idea how they managed to distribute it to the subscribers in a timely manner. -- Ed.]
The argument seems to always come down to the difference between agglutination and separate roots. Or "Eastern" and "Western" style languages, broadly speaking (I know it's an over-simplification). Some people think every concept needs its own root, others are happy to begin with some basic set and modify. Two incompatible systems of thinking.
I consider Esperanto to be a good compromise between "Western" root-based thinking and "Eastern" agglutinative thinking (again, very roughly speaking). Having a Hungarian background, I delight in the simple elegance of Esperanto word-building. [Unlike just about every other language in Europe, Hungarian is not Indo-European; it comes from a completely different language family. Thus, it is as unrelated to Esperanto as English is to Arabic, for example. -- Ed.]
I think there is something for everyone in Esperanto, no matter what your linguistic background, and that this is one major reason why it is the most successful of the auxiliary languages.
The other night I was having dinner here in the Detroit area with Koralo Chen, an Esperanto speaker from China whose home is very close to Hong Kong. I presented this objection to him. Koralo Chen replied that he had often heard this objection but that it made little sense to him. In his part of the world the major languages are completely unlike each other. Knowing Chinese doesn't help with learning how to speak Korean or Japanese, for instance.
I can see why this objection makes good theoretical sense to some Westerners, but it makes no sense at all to those Chinese who, like Koralo Chen, need not a theoretically perfect but very practical language to learn for international communication.
Manuel M Campagna:
The International Auxiliary Language Association (IALA) researched this point scientifically, and came up with the conclusion that while there are 6 170 languages in the world (not including dialects) at this time, there is no evidence that a language with one word from each language would be more popular. Indeed it would be an unworkable hodgepodge.
This objection has been handled at length by Prof. Pierre Janton. In brief, there are two major facts to take into account. First of all, there are thousands of languages in the world and if Esperanto attempted to create its vocabulary from even 10 % of them you would simply get a language which would be very difficult to learn for everybody instead of the real Esperanto which is relatively easy for all.
Secondly, the world-wide spread of Euro-American science, commerce, technology, geopolitics, entertainment, etc., has meant that many technical terms from "Western" languages have entered the vocabulary of many other languages too. So, in fact, the European basis for Esperanto's vocabulary is a lot more international than appears at first sight.
However, the whole argument is really irrelevant because the internationalism of Esperanto -- or of any other planned language -- cannot reside in its vocabulary for the reason just mentioned.
In fact, what makes Esperanto a truly "international" language (as distinct from a "world" language like English) is its extraordinary semantic flexibility which allows speakers from different language families to translate their own thought patterns directly into Esperanto and produce something which is perfectly intelligible and grammatically correct.
Manuel M Campagna:
Non-IE speakers thank you for your protective attitude, but they can and do fend for themselves, and Esperanto is very popular in Hungary, Estonia, Finland, Japan, China, Vietnam... The current [1995-1998] president of the Universal Esperanto Association is a Korean university professor of Economics. The most attended international meeting in 5000 years of Chinese history was the 1986 Universal Congress of Esperanto in Beijing, being the largest both by the number of delegates and the number of countries represented.