Throughout history, various lingua franca have emerged, serving as common languages for diverse populations: Aramaic, Greek, Latin, and French. While the influence of British imperialism and American culture established English as the dominant global language, there have been many endeavors to develop a universal language for humanity. Esperanto stands as the most well-known attempt, but it is far from the only one. Here are 10 others worth noting.
10. Volapük

In 1879, during a sleepless night, Johann Schleyer, a German Catholic priest, claimed to receive a divine message urging him to create a universal language. His design aimed for simplicity, utilizing a basic system of roots borrowed from European languages, so much so that they became barely recognizable from their original forms. Volapük gained rapid popularity among the middle class, seen as a valuable tool for international communication before English's dominance in Europe was cemented by American economic power. However, Schleyer’s insistence on including umlauts led to its downfall. He argued, “A language without umlauts sounds monotonous, harsh, and boring.”
The presence of umlauts made the language appear too foreign for many, especially in the United States. Schleyer resisted any reforms, even creating his own faction within the movement. Volapük then fractured into rival variants, all of which were eventually overshadowed by Esperanto. Up until the 1960s, the phrase “to speak Volapük” was a French idiom meaning to speak nonsense or gibberish, although the phrase became less common until Nicolas Sarkozy revived it in 2010 during his criticism of the UN climate summit talks, briefly confusing his interpreters.
9. Blissymbols

Charles K. Bliss developed a unique communication system known as Blissymbols, aiming to create a universal written language usable by people across the world, regardless of their native tongue. While working in Shanghai as a photographer and filmmaker during World War II, Bliss became captivated by Chinese characters, their rich history, and the possibility of a shared written system for speakers of different languages. This inspiration led him to design a more systematic version called Blissymbols, which blended elements from mathematics, molecular formulas, and electrical symbols.
Some of the symbols were pictographs, depicting tangible objects like a house or the Sun, while others were ideographs, symbolizing abstract concepts such as the mind or the act of giving. These symbols were designed to be simple to draw and could be combined to convey complex ideas, facilitating communication between people of diverse linguistic and cultural backgrounds. With an initial set of 10 basic icons, these symbols could be merged to represent intricate meanings. Bliss’s ultimate aim was to create a language that would enable humans to communicate without misunderstanding, which he believed was at the heart of much of the world’s suffering.
Although Blissymbols did not become a widely adopted tool for international communication, they found a practical application in the 1970s, aiding individuals with cerebral palsy in their communication. In the mid-1980s, 12-year-old Rachel Zimmerman created the Blissymbolic Printer, a device that allowed non-verbal patients to communicate efficiently via a computer screen. This system continues to serve thousands of physically disabled individuals today.
8. Modern Indo-European

The Dnghu Association is a European nonprofit group focused on revitalizing the ancient North-West Indo-European language as a shared language for the European Union, aiming to promote it as an international auxiliary language. The Indo-European family is the largest modern language group, encompassing the Germanic, Romance, Slavic, Celtic, Baltic, Albanian, Hellenic, Iranian, and Indo-Aryan language branches, along with the extinct Tocharian and Anatolian groups. Some linguists consider the North-West Indo-European language to be the ancestor of modern Germanic and Romance languages, and therefore, a revived Modern Indo-European is envisioned as a “natural and common” language for all of Europe (excluding the Basque, Hungarians, Estonians, and Finns).
The organization’s name comes from the Indo-European term “dnghu,” meaning “tongue,” which gave rise to the Latin “lingua” and the English “language” (and “tongue,” via Germanic). The language was originally called Europaio, but the name was changed to Modern Indo-European to distinguish the project from artificial languages like Esperanto. Critics of the movement have labeled it as the work of amateurs with a political agenda, accusing them of disregarding legitimate Indo-European linguistic research. Those interested in learning Modern Indo-European can access the complete grammar online through Creative Commons.
7. Interglossa And Glosa

In 1943, linguist and biologist Lancelot Hogben introduced “Interglossa: A draft of an auxiliary for a democratic world order, being an attempt to apply semantic principles to language design.” He proposed a language devoid of flexions and endings, sourcing its vocabulary from Greek and Latin, while adopting the syntax and word order of Chinese.
Hogben's philosophy centered around the belief that 'the best grammar is no grammar,' a concept drawn from an earlier Latin-based auxiliary language known as Interlingua. Surprisingly, the language did not catch on with the British public, who were preoccupied with the war against fascism. As a result, it remained inactive until 1960, when Ron Clark, a passionate scholar, rediscovered it. Clark was later joined by Wendy Ashby in 1972, and after Hogben’s death in 1975, they renamed the language Glosa to reflect a move to a more phonetic spelling system, one that was less constrained by Greek conventions.
Each word in Glosa stands for an idea and can serve as a verb, noun, adjective, or preposition, with grammar defined by operator words and word order. Glosa continues to have a strong online presence and can be learned through freely available resources.
6. Real Character

In the 17th century, Dr. John Wilkins made an early attempt to create a universal character system akin to Blissymbolics. In 1668, he was commissioned to write 'An Essay Towards a Real Character, And a Philosophical Language.' Wilkins, known for his esoteric pursuits in theology, cryptography, transparent beehives, music, and the potential for lunar travel, aimed to develop a language with universal linguistic traits. This language would replace Latin as the lingua franca of Europe and help spread 'true religion.' His vision was to create 'real characters' with fixed meanings, universally understandable across language barriers, much like mathematical symbols are universally recognized.
He regarded Hebrew as the most suitable language, considering it had the fewest redundant radicals and was closest to the language of God. He also created a philosophical language that could be both spoken and written. Unlike Latin, however, this language had no irregularities or exceptions. He accomplished this by attempting to categorize everything in the universe into 40 classes, each represented by two-letter monosyllables. These classes were further split into 'differences' by adding a consonant, and then into 'species' with an added vowel. The term 'De', meaning 'element', served as the foundation for 'deb' ('fire'), which evolved into 'deba' ('flame'). The true structure of the character and philosophical language systems that Wilkins created were actually rather mismatched. Renowned writer Jorge Luis Borges later criticized Wilkins’ approach, calling it unavoidably arbitrary.
5. Solresol

In the early 19th century, musician Jean Francois Sudre devised a method of linking the letters of the alphabet to musical notes. This allowed him to pose questions to his students by playing his violin, with their responses made on the piano. Sudre believed this technique, later called Telephonie, could be a form of long-distance stenography, but the Ministry of War viewed it as a potential form of military communication. Despite successfully conveying messages like 'You will destroy the bridge at dawn' using a bugle, the military concluded its practical use was limited.
After repeated unsuccessful attempts to persuade the army and navy, Sudre shifted focus, aiming to use the system to help the blind and deaf communicate. In 1829, Sudre abandoned Telephonie in favor of a new system, the musical language Solresol. This language was based on seven phonemes from the Western musical scale: 'do re mi fa so la si' (known as 'ti' in English). Words in Solresol were formed by combinations of musical notes, allowing communication through speaking, singing, humming, or playing an instrument. Sudre even devised methods to convey the language using the ROYGBIV color spectrum, hand gestures, and numerical tapping.
The language intentionally restricted its vocabulary to just four phonemes, which combined to create only 2,660 distinct words. This is a far smaller number than what is found in natural languages. Additionally, it featured a straightforward grammar system that allowed words to have reversible meanings. For example, the word 'Misol' meaning 'good' could be reversed to 'solmi' meaning 'bad', which is just one illustration of the structure. Despite Sudre publishing Solresol dictionaries in various languages and giving demonstrations to royalty and eager audiences, the language gradually faded after his death. However, it has seen a revival on the internet in recent years.
4. Ido

Following the fall of Volapük, Esperanto emerged as the most widely embraced artificial language, first introduced by Dr. Lazarus Zamenhof in 1887. A competing auxiliary language, Idiom Neutral, also appeared, created by former Volapük enthusiasts. The aim of Idiom Neutral was to select words based on their commonality across the seven major European languages. Though the language was often criticized as harsh-sounding and grammatically underwhelming, it played a crucial role in the development of another proposed auxiliary language: Ido. Esperanto was grounded in the document 'Fundamento de Esperanto', which outlined its essential principles. This led to a divide among Esperantists, with traditionalists opposing any reform and others pointing out issues with Esperanto, such as cumbersome circumflex letters, difficult conjugation, and the awkward use of '-j' for plurals.
Zamenhof's erratic behavior contributed to a division, giving birth to Ido, which took its name from the Esperanto word for 'offspring' and aimed to strike a middle ground between Esperanto and Idiom Neutral. Ido originated from the 1907 Delegation for the Adoption of an International Auxiliary Language in Paris, where Esperanto was selected as the preferred choice, but Ido pamphlets were secretly left underneath the tables of delegates. Despite its roots as a reformed Esperanto, tensions soon arose, leading to Ido forming a separate movement that criticized Esperantists for their dogmatic and anti-scientific stances. They argued that Ido was a rational advancement on par with the metric system. Nonetheless, Esperanto remained the most successful auxiliary language in history, despite the opposition from these dissenters.
3. Lojban

In 1955, the Loglan project was initiated to explore the Sapir-Whorf hypothesis, which posits that the language one speaks shapes the way one thinks. Dr. James Cooke Brown's work on this was published in the 1960 edition of Scientific American, and Loglan later appeared in several science fiction works, including Heinlein’s *The Moon is a Harsh Mistress*. The language was designed to be rooted in predicate logic, using vocabulary from the six most widely spoken languages worldwide, arranged in a logical and symbolic manner with a straightforward, unambiguous grammar. Brown believed that this structure would enhance the cognitive abilities of its speakers.
The growing interest in Loglan prompted others to contribute their ideas, which led to conflicts with Brown, who sought to claim intellectual property rights. This resulted in power struggles between him and the Board of Directors at The Loglan Institute, which caused many volunteers to leave and progress became frozen. After a failed attempt to claim trademark infringement in 1992, the open-source version of Loglan, called Lojban, was created and has gained significant popularity on the Internet over the past two decades.
Lojban supporters highlight its many benefits, including the efficient expression of emotions through attitudinals, which function as verbal emoticons. Additionally, they emphasize its clear syntax, expanding vocabulary, adaptable pronunciation, and cultural neutrality. Another advantage is that the language is highly machine-readable, which means it could potentially be used in the future to communicate with artificial intelligences.
2. Ithkuil

This constructed language was created by John Quijada with the goal of developing what humans would never naturally create without intellectual effort: an idealized language aiming for the highest degree of logic, efficiency, detail, and precision in cognitive expression via spoken language, all while minimizing ambiguity, vagueness, illogic, redundancy, polysemy (multiple meanings), and the overall arbitrariness that is prevalent in natural human language.
Quijada drew inspiration from Esperanto's political philosophy and a French progressive rock concept album, which was entirely sung in an alien language devised by the lead singer. His early language projects were mixed in success: Mbozo, a Romance/Germanic hybrid with African-like phonology, and Pskeoj, with a vocabulary made by typing randomly on a typewriter. As Quijada delved into the study of exotic languages, he became fascinated with the idea that each language excels at something unique that no other language can do better. Ithkuil was created to synthesize the strengths of various languages into one highly efficient language capable of conveying information with utmost precision and clarity.
Ithkuil allows for words like “Onxeizvakcispourboi,” which means 'the emotional and psychological effect of realizing too late that one’s actions and their consequences have slowly extinguished the hopes your lover had that this would evolve into a long-term monogamous relationship.' The language gained unexpected fame in Russia after being mentioned in the popular science journal Computerra, sparking a bizarre surge of popularity linked to a fringe academic movement called 'psychonetics.' This mystical self-help philosophy focused on developing 'technologies of human consciousness.' Its ultimate goal was perfect perception: 'A psychoneticist must have nothing unconscious. Everything must be conscious. This is the same goal as Ithkuil. Human beings have a linguistic essence, but we are in a transitional stage to some other essence. We can defeat and conquer language.'
Quijada has distanced himself from Ithkuil, referring to it as a '25-year itch' that he successfully scratched. He expressed his thoughts with the sentence “Eipkalindholl te uvolilpa ipcatorza uxt ri’ekcuobos abzeikhouxhtou eqarpa? dhai’eickobum ot euzmackuna? xhai’ekc’oxtimmalt te qhoec ityatuitha?,” which translates to: 'I am privileged to have had the rare experience of having what I think of as a hobby propel me to faraway places where one encounters new ideas along with new cultures and new peoples generous in their hospitality and respect, leading me to humble introspection and a new appreciation for the human spirit and the wonders of the world.'
1. aUI

Among the most unusual constructed languages is aUI, which translates to 'space-spirit-sound.' Created by Austria-born Iowa psychologist John W. Weilgart, it was allegedly inspired by a claim that he learned it as a child from a green alien humanoid who revealed that aUI was the universal language of logic used throughout the cosmos. Unlike other attempts to create a universal language, aUI is not connected to any existing human language and does not follow naturalism. Weilgart sought to develop a language that would allow free expression of ideas while remaining deeply rooted in inherent meaning to prevent the manipulation of meaning and the use of metaphor to obscure communication. He identified what he believed to be 31 universal elements of meaning, each associated with a vowel or consonant.
For example, the combination of 'p' ('before') with 'O' ('feeling') creates the word-concept 'pO,' meaning 'anticipation.' In another case, 'f' ('this') and 'u' ('human') combine to form 'fu,' meaning 'this-human,' or 'me.' Similarly, 'b' ('together') combined with 'u' results in 'bu,' meaning 'together-human,' or 'you.' In aUI, all words are inherently tied to their root meanings, which Weilgart believed would reduce prejudice and misunderstanding.
Weilgart was convinced of the universal relevance of his language: 'The Language of Space is the cosmic communication, whose elements can be learned in an hour. It is the primeval language of the Logos of pure reason that takes our human race back before the confusion of Tongues at the Tower of Babel.' While intriguing, the language has found little modern support, as it is highly counterintuitive to the standards of human linguistics. Perhaps we’ll have to wait for the Zeta Reticulans to send native-speaking instructors and audiobooks.
