In older science fiction, it was assumed that future people of different cultures would speak to one another in Esperanto, or in a fictionalized version of it. Esperanto is a real-world invented language created by L. L. Zamenhof in 1887, which is highly simplified, and can be learned by an English-speaker in about 1/10th the time it would take an English-speaker to learn French. It is also a language which largely lacks idioms which cannot be literally translated, such as saying ‘I am blue’ in English to mean ‘I am sad.’ (The English translation of the German sci-fi series, Perry Rhodan, has future slang terms with Esperanto roots, even though that’s not in the original German text.)
In early science fiction, Esperanto was new linguistic technology which seemed to scream ‘futuristic.’ That impression has changed, in large part because so many people on the planet don’t want to have to learn the international language Esperanto when they have already learned Chinese, Arabic, Spanish or English as their international language. It is commonly said that Esperanto has ‘failed.’ But since it has gone from just-an-idea with one speaker, Dr. Zamenhof, in 1887 to a language estimated to have 2-4 million speakers and maybe more who could recognize the language and communicate in it on a basic level if they had to.
A later idea of how future people would solve the interplanetary language problem was a ‘universal translator’ device like used on Star Trek. The Star Trek device could start translating without hearing a word of a new alien tongue, as far as we could see on the show. But in the real world, translation by computer is hard. There are always mistakes. Would YOU like to create a treaty with the Klingons using only a ‘universal translator,’ or would you opt for using bilingual beings as translators so they could catch the mistakes and ambiguities?
There has also been the idea that in the future, English or a version of English will be the interplanetary universal language. On Earth, our experience has been that a country with great military and economic power can induce foreign peoples of less power to learn their language, as the British Empire spread English and English-learning around the world. But our experience on Earth has also been that the most popular international language doesn’t stay so popular forever. Greek was an international language in the ancient world, and was learned by educated persons in many nations from Egypt to Israel to Rome. As Greek national power waned and Roman power grew, Latin became an international language. It continued to be an international language for a long time because the Church was centered in Rome, and the Catholic Church still uses Latin for international communications purposes. (There used to be an ATM machine in the Vatican with Latin instructions!) Later French became the language of diplomacy, and only later did English start being used for international purposes. In the future with the growing power of China and of the Muslim world, perhaps Mandarin Chinese or Arabic may have a turn at being the most popular international language.
Adopting a created language like Esperanto is a different sort of thing. It does not belong to any one nation on Earth, and it is highly unlikely that if Esperanto moves out into the interplanetary world that any Esperanto-speakers will claim it belongs particularly to Earth. Like other created international languages, it belongs to the people who have taken the trouble to learn it in order to communicate better with others. It may seem that Esperanto or other similar languages moving into common use would require loads of people (and space aliens) to become more idealistic. But actually, it is pragmatic. I learned Esperanto well enough to read it by spending 2 month studying a book on it in my spare time while I was in college. This is a short investment in time as language-learning goes. Imagine how an international or interplanetary project would be enhanced by asking (or ordering) the participants to spend the small amount of time it would take to learn to communicate with others in Esperanto.
Esperanto is not the first created language ever made as an international language. There were many such projects before Esperanto, such as Universalglot or Volapuk. Volapuk actually had a following and language clubs at one time! After Esperanto, there were languages such as Ido (an Esperanto dialect) and Interlingua. There are also languages like Slovio, a pan-Slavic language.
In the future, a new international or interplanetary language could arise that is no relation to Esperanto, but has similarities in easy of learning. It’s possible that English speakers might meld English word roots with a simplified, Esperanto-like spelling system and grammar to create a new language easy for those who already speak English as a first or second language. Or Chinese speakers, or Arabic speakers. Now that Esperanto and other simplified languages have been created, the principles are available to anyone.
What about Klingon for an international language on real-world Earth? There used to be internet rumors of how an English-speaking Star Trek fan had communicated with a Japanese Star Trek fan in Klingon. As a massive fan of Star Trek, I looked into that. I wanted to translate a few simple sentences into Klingon. But I found that Klingon had no words for the key words in my sentences, like ‘cat’ and ‘rat.’ And no mechanism for creating new words, which Esperanto has. And since Klingon is the intellectual property of Paramount Pictures, who hired the man who made up the Klingon language, we really can’t use it for an international language without permission. So an Esperanto club in Poland can’t transfer its loyalty to Klingon as an international language, as Volapuk clubs transferred their loyalty to Esperanto once Esperanto was invented, because Klingon isn’t in the public domain!
As writers, if we like the interplanetary-language concept as a plot device, we are free to create our own interplanetary language— language inventing is a legit hobby now and there are web sites that may help you— or you can used Esperanto (or Volapuk or Universalglot) as a pre-fab language in your work. Since they are international languages meant for use, they were all ‘born’ in the public domain, and are old enough that they would be in the public domain now anyway.
Esperanto is the best developed international language. There are free Esperanto learning websites and cell phone apps like Duolingo, there are still a few Esperanto shortwave broadcasts, and even more broadcasts in Esperanto on internet radio— including one on Vatican radio. Also, the Bible has been available in Esperanto from early on. The language’s creator, Zamenhof, was a Polish Jew and spoke Hebrew as well as many other languages, and he translated the Old Testament. Here is a sample: ‘En la komenco Dio kreis la chielon kaj la teron.’ [Genesis 1:1] The New Testament was translated by the British Bible society, and the Deuterocanonical books— the books in Catholic Bibles that modern Jewish and Protestant Bibles don’t have— are also now available. So the Esperanto Bible— especially the Zamenhof-translated Old Testament— is a treasure trove of grammatically proper Esperanto stuff to quote.
I might warn other language geeks: don’t give out long solid blocks of text in Esperanto or your own fictional language or any language other than English (or whatever other language you are writing in.) It will confuse or annoy many readers, while using a word or phrase or two may be able to be ignored by people who don’t like that sort of thing. Sometimes, less is more!
Imagine a futuristic story in which language diversity is a problem. How will your characters solve the problem? How will they get others to agree to their solution? What will be the drawbacks and benefits of the solution your characters choose?
A major corporation builds a massive factory or mine or something, and has to get workers from many linguistic groups. The corporation hires linguists to create a simple language for the corporation workers to use with one another. Over time, children are born from ‘mixed marriages’ among the workers who use the (copyrighted) corporation-owned language as their primary or only language— and they can’t leave to work for other corporations because they cannot use their native language without corporate permission!
Your characters believe that Esperanto (or another interplanetary language) is evil and threatens the survival of other languages and their related cultures. Languages like Chinese and English and German are dying out the way American Indian languages are dying today (many Indian languages in the US have only a handful of elderly speakers left alive right now— when they die, the language is dead, without any native speakers.)