Related Searches



Lojban is a constructed, syntactically unambiguous human language based on predicate logic. Its predecessor is Loglan, the original logical language by James Cooke Brown.

Development of the language began in 1987 by The Logical Language Group (LLG), who intended to realize Loglan's purposes as well as further complement the language by making it more usable, and freely available (as indicated by its official full English name "Lojban: a realization of Loglan"). After a long initial period of debating and testing, the baseline was completed in 1998 with the publication of The Complete Lojban Language.

The name "Lojban" is a combination of loj and ban, which are short forms of logji (logic) and bangu (language), respectively. Due to its name, Lojban is sometimes misunderstood to be within some exclusive domains such as formal logic or computer programming; however, it is usable for daily conversation. While it is meant to be capable of handling highly logical concepts, it is also highly flexible. To whatever degree the speaker wishes, it can resemble its natural, programming, or other constructed counterparts, and it can be poetic, ambiguous, precise, or neutral.

The principal sources of its basic vocabulary were the six (at the time) most widely spoken languages: Arabic, Chinese, English, Hindi, Russian, and Spanish, chosen to reduce the unfamiliarity or strangeness of the root words to people of diverse linguistic backgrounds. The language has drawn on other constructed languages' components, a notable instance of which is Láadan's set of indicators. Also Toki Pona and Esperanto have mutuality with Lojban to some extent.

In this article, explanations of its grammatical aspects will mostly be based on The Complete Lojban Language; the Latin alphabet mode will be used for the orthography.


Origin (1955–1987)

Lojban has a predecessor, Loglan, a language invented by James Cooke Brown in 1955 and developed by The Loglan Institute. Loglan was originally conceived as a means to examine the influence of language on the speaker's thought (an assumption known as Sapir-Whorf hypothesis).

As Brown started to claim copyright on the language's components, restraint was laid on the community's activity. In order to circumvent such control, a group of people decided to initiate a separate project, departing from the lexical basis of Loglan and reinventing the whole vocabulary, which led to the current lexicon of Lojban. In effect they established in 1987 The Logical Language Group, based in Washington DC. They also won a trial over whether they could call their version of the language "Loglan".

Initial development (1987–1997)

The freeze period (1997–2002)

Following the publication of The Complete Lojban Language, it was expected that "the documented lexicon would be baselined, and the combination of lexicon and reference grammar would be frozen for a minimum of 5 years while language usage grew. As scheduled, this period, which has officially been called the "freeze", expired in 2002. The speakers of Lojban are now free to construct new words and idioms, and decide where the language is heading.

Post-foundation (2002–)

Lojban still shares many of the characteristics of Loglan:

  • Has a grammar that is based on predicate logic, designed to express complex logical constructs precisely.
  • Has no irregularities or ambiguities in spelling and grammar (although word derivation relies on arbitrary variant forms). This gives rise to high intelligibility for computer parsing.
  • Is designed to be as culturally neutral as possible.
  • Allows highly systematic learning and use, compared to most natural languages.
  • Possesses an intricate system of indicators which effectively communicate contextual attitudes or emotions.
  • Does not have simplicity as a design criterion.

Literature and vocabulary development

Lojban can be an intellectual device for creative writing and is deemed to have many potential aspects yet to be discovered or explored.

See also the proposed fourth tense of Lojban discussed by Arthur Protin, Bob LeChevalier, Carl Burke, Doug Landauer, Guy Steele, Jack Waugh, Jeff Prothero, Jim Carter, and Robert Chassell, as well as ZAhO tenses, the concepts which "average English speakers won't recognize" because most of them (the concepts) "have no exact English counterpart".

Like most languages with few speakers, Lojban lacks much of an associated body of literature and its creative extensions have not been fully realized (the true potential of its attitudinal system, for example, is considered unlikely to be drawn out "until and unless we have children raised entirely in a multi-cultural Lojban-speaking environment). Also such collective or encyclopedic sources of knowledge like the Lojban Wikipedia, which may help expand the language's lexical horizon, are in need of growth.

Presently accessible Lojbanic writings are principally concentrated on the, though there exist independent Lojbanic blog/journal sites as well. The Lojban IRC (or its archive) has a gathering of Lojbanic expressions too, but its grammatical correctness is not always guaranteed. These available materials on the internet include both original works and translations of classic pieces in the field of natural languages, ranging from poetry, short story, novel, and academic writing. This has been paralleled with a chrestomathy project aiming to produce a collection of translated writings in order to show wide samplings of various language, hopefully longer than 10000 words and with a variety of genres and styles (see also - External link: Literature). Exemplary works that are already available include:

Other translation projects include:

  • Eaton Interface: a translation of the Helen Eaton concept list into Lojban.
  • Parliamentary Rules: Lojban terms for parliamentary actions.
  • Lojban Adventure: a Lojban version of the classic Colossal Cave text adventure game.

Compound words (lujvo) and borrowed words (fu'ivla) are continually increasing as the speakers find demands. The number of root words (gismu) and structure words (cmavo) are basically unchanging, but new inventions are to be accepted as experimental components. In fact, it has been noticed that particular inclination or disproportion exists in the available vocabulary. Cortesi has pointed out the lack of certain terms for mathematics and geometry (although this demand may now be disputed as the current set of Lojban vocabulary does actually allow speakers to express such notions as steradian (stero), trigonometric tangent (tanjo), multiplicative inverse (fa'i), matrix transpose (re'a) among a number of other kinds of operators or metric units). Other instances which require speakers to construct noncanonical words:

  • There are few (almost non-existent) entries of African country names on the official list of root words while other country names (especially those with large populations of speakers of the six source languages) are covered to a remarkable extent.
  • Such distinction as between palne (tray) and palta (plate) exist while no distinction between "illustration" and "photography" is made by the available set of gismu (that is, no exclusive root word for "photography" exists except the generic pixra (picture)) (see also - Grammar: Morphology: brivla: gismu).

Development of learning aids

Apart from the actual practice of the language, some members of the community and LLG have been endeavoring to create various aids for the learners. The Complete Lojban Language, the definitive word on all aspects of Lojban, is one of them, finalized in 1997. Some of the projects in varying stages of completeness are:

  • Phrasebook: Lojbanic Phrasebook Project, CVS/Wiki Lojban Phrasebook, Pocket Dictionary
  • Parser: Lojban Parser/Machine Grammar (by Robin Lee Powell), jbofi'e (by Richard Curnow), valfendi (by Pierre Abbat)
  • Database: jbovlaste (by Robin Lee Powell), Reference Database (by Matt Arnold on DabbleDB)
  • Others: Lojban/Logic book and webpage (by John Clifford), TLI Loglan Interface (by Steven Belknap and Bob LeChevalier)

(see also - External link: Learning Courses/Resources)

A dedicated Lojban popup dictionary as a Firefox add-on has been suggested, but is still in the level of speculation as the present lexing and parsing system of Lojban does not cover JavaScript.

Community development

Currently, Lojban's learning resources available on the internet are available mainly to speakers of English, French, Spanish, Russian, Hebrew, and Esperanto, to varying degrees.

Disproportion in the community population is still noticeable. It is reasonably hoped among Lojbanists that more people from different cultural/linguistic backgrounds join the community in order to maintain and further complement the intended neutrality of the language. (see also - Community)

Future goals

While the initial aim of the Loglan project was to investigate the Sapir–Whorf hypothesis, the active Lojban community recognizes additional goals for the language to be attained in the future, including but not limited to:



Lojban has 6 vowels and 21 consonants. Some of them have, apart from the preferred/standard sounds, permitted variants intended to cover dissimilitude in pronunciation by speakers of different linguistic backgrounds.

There are also 16 diphthongs (and no triphthongs). Distinction between diphthongs and monophthongs can be made by inserting an apostrophe in the Latin alphabet mode.

The sounds may be allophoned.

For those who, given their native language background, may have trouble pronouncing certain consonant clusters, there is the option of inserting buffer vowels between them, as long as they differ sufficiently from the phonological vowels and are pronounced as short as possible. The resulting added syllables are completely ignored by the grammar, including for the purposes of stress determination.


Lojban may be written in different orthography systems as long as the system used satisfies the required regularities and unambiguities. Some of the reasons for such elasticity would be as follows:

  1. Lojban is rather defined by the phonemes (spoken form of words), therefore, as long as they are correctly rendered so as to maintain the Lojbanic audio-visual isomorphism, a representational system can be said to be an appropriate orthography of the language;
  2. Lojban is meant to be as culturally neutral as possible, so it is never crucial or fundamental to claim that some particular orthography of some particular languages (e.g. the Latin alphabet) should be the dominant mode.

Some Lojbanists extend this principle so as to claim that even an original orthography of the language is to be sought.

This article will use the common Latin alphabet mode.


Lojban has 3 word-classes: predicate words, structure words, and name words. Each of them has uniquely identifying properties, so that one can unambiguously recognize which word is of which part of speech in a string of the language. They may be further divided in sub-classes. There also exists a special fragmental form assigned to some of the words, from which longer words can be compounded.

Syntax and semantics

The language's grammatical structures are "defined by a set of rules that have been tested to be unambiguous using computers", which is in effect called the "machine grammar". Hence the characteristics of the standard syntactic (not semantic) constructs in Lojban:

  • each word has exactly one grammatical interpretation;
  • the words relate grammatically to each other in exactly one way.

Such standards, however, are to be attained with certain carefulness:

The computer-tested, unambiguous rules also include grammar for 'incomplete' sentences e.g. for narrative, quotational, or mathematical phrases.

Lojbanic expressions are modular; smaller constructs of words are assembled into larger phrases so that all incorporating pieces manifest as a possible grammatical unity. This mechanism allows for simple yet infinitely powerful phrasings; "a more complex phrase can be placed inside a simple structure, which in turn can be used in another instance of the complex phrase structure".

Its typology can be said to be basically Subject Verb Object and Subject Object Verb. However, it can practically be anything:

  • mi prami do (SVO)
  • mi do prami (SOV)
  • do se prami mi (OVS)
  • do mi se prami (OSV)
  • prami fa mi do (VSO)
  • prami do fa mi (VOS)

Such flexibility has to do with the language's intended capability to translate as many expressions of natural languages as possible, based on a unique positional case system. The meaning of the sentence {mi prami do} is determined by {prami} realizing, with its own predefined "place structure", a specific semantic relation between {mi} and {do}; when the positional relation between {mi} and {do} changes, the meaning of the sentence changes too. As shown above, Lojban has particular devices to preserve such semantic structure of words while altering their order.

As befits a logical language, there is a large assortment of logical connectives. Such conjunction words take different forms depending on what they connect, another reason why the (standard) Lojbanic expressions are typically precise and clear.

Multiple predicate words may be linked up together so as to narrow the semantic scope of the phrase. In skami pilno "computer user(s)", the modifying word skami narrows the sense of the modified word pilno to form a more specific concept (in which case the modifier may resemble English adverbs or adjectives).

One could go still farther, adding a quite extreme example of its syntactical flexibility.

Lojban can "imitate" easily even Amerindian one-word sentences like this one:

  • Nootka: inikwihl'minik'isit
  • English: (about) Several small fires were burning in the house.
  • Lojban: so'i cmalu fagri puca'o jelca ne'i le zdani
  • Gloss: many small fire past-continuing burn inside the house (Translation after English)
  • Lojban: zdane'ikemcmafagyso'ikemprununjelca (so-called lujvo or compound word mainly using the underlying rafsi or roots according to strict compositional rules)
  • Gloss: (about) house-inside type-of small fire multitude type-of past event type of burning

The Nootka one-word sentence breaks down a bit differently as:

inkiw (fire/burn) -ihl (in-the-house) -'minik (plural) -'is (diminutive) -'it (past-tense)

which can be readily expressed in Lojban the same way:

  • Lojban: fagykemyzdanerso'icmapru
  • Gloss: fire-type-house-inside-many-small-past-event


Common expressions

Lojban literal meaning English
coi/co'o [greetings!]/[farewell!] hello/good-bye
pe'u [please!] please
ki'e [thankful!] thank you
.u'u [pity!] I'm sorry
xu do se glibau/jbobau [true-false?] you is-a-speaker-of-English/Lojban-language Do you speak English/Lojban?
ti/ta that-here/that-there this one/that one
mi na jimpe I [false] understand I don't understand
go'i the-last-bridi yes/that's true
na go'i [false] the-last-bridi no/that's false
la'u ma being-a-quantity-of what how much/many?
ma jdima what is-the-price-of what's the cost?
ma stuzi lo vimku'a what is-an-inherent-site-of that-which-is toilet Where's the toilet?

Some unique Lojbanic expressions

  • pei .o'ucu'i
    [?] [relaxation!] [neutral]
    Are you no longer in pain?
  • mi nelci ko
    I is-fond-of you-[imperative]
    Make me be fond of you!
  • le cukta be'u cu zvati ma
    that-which-is-described-as book [need!] is-at what
    Where's the book? I need it!
  • ko ga'inai nenri klama le mi zdani
    you-[imperative] [me-the-social-inferior!] inside-type-of come that-which-is-described-as having-to-do-with-me house
    I would be honored if you would enter my residence.
  • le nanmu cu ninmu
    one-or-more-specific-things-which-I-describe-as "men" are women
    The man/men is/are a woman/women.
  • seri'agi mi jgari lei djacu gi mi jgari le kabri
    With-physical-effect I grasp the-mass-of water, I grasp the cup.
    Therefore I grasp the water, I grasp the cup.

Tongue Twisters

  • lo'u lu le la li'u le'u
  • le crisa srasu cu rirci crino
  • tisna fa la tsani le cnita tsina lo tinci tinsa
  • la bab. zbasu loi bakyzbabu loi bakygrasu
  • mi na djuno le du'u klama fa makau la makaus. makau makau makau



The Internet

The activities of Lojban speakers are mostly via the Internet:

  • A user-maintained site, attempting to reflect a cross section of the Lojban community outside of the LLG.
  • Lojban IRC ( #lojban): Based on the Freenode IRC network. One may use a web interface as an alternative to IRC clients.
  • Lojban Mailing List: A beginner-oriented means to talk/learn about the language.
  • jbovlaste: An official, dictionary editing interface created by Jay Kominek, updated by Robin Lee Powell. People can post new Lojbanic words with definitions and examples, or vote for such experimental words.
  • jbobac: A web-based forum that has posts/threads made up mainly of sound files.
  • samxarmuj/The Lojban Moo: A multi-user virtual environment, similar to the old text adventure games. A guide is given here
  • le jbopre pe lj's Journal: A communal Lojban blog.
  • lojban-valsi: A-word-a-day mailing list on the Yahoo! Groups.
  • : A community in which people may practice their Lojban, ask questions, propose Lojban-related ideas, etc.
  • Main Page: The Lojban Wikipedia, where discussions may be conversed in English.

The Logfest

Gatherings of Lojbanists have been organized in USA annually since as early as 1990, called Logfest. It is mostly informal, taking place on a weekend, with the only scheduled activity being the annual meeting of the LLG. Those who cannot be present may still be involved via IRC. Activities may be whatever the attendees want to do: Lojban conversation, lessons, technical discussions, or socializing.


The total number of Lojban speakers is unknown.

According to, places known to have concentration of Lojbanists are:

  • Australia, Israel, United States

Also shows that, as of August 2007, some people from following countries are interested in or enthusiasts of the language:

  • Argentina, Canada, China, Estonia, France, Germany, Ireland, Mexico, The Netherlands, New Zealand, Norway, Russia, Thailand, Ukraine, United Kingdom, Venezuela.

It is generally noticed that there is little participation from Hindi speaking people, in spite of the etymological nature of Lojban vocabulary.

Below are some of the notable personalities who have contributed to the development of Lojban:

  • Bob LeChevalier (aka lojbab): the president of the LLG.
  • John Cowan: the author of The Complete Lojban Language.
  • Jorge Llambías (aka xorxes): one of the most active Lojbanists, having done several translations. He is also a prominent figure on the mailing list, helping the beginners with the language.
  • Matt Arnold (aka epkat): one of the most active Lojbanists. He has been contributing to the translation project and software development.
  • Nick Nicholas (aka nitcion): an Australian linguist. He is the first fluent Lojban speaker (although he insists that he was the second; he is known to be excessively modest). He has done a lot of Lojbanic writing, including Lojban For Beginners coauthored by Robin Turner.
  • Robin Lee Powell (aka camgusmis): the current webmaster of He provides the machine and bandwidth from which the site is served. He has also written several Lojbanic materials including a novel-sized story.
  • Robin Turner: a British philosopher and linguist living in Turkey. He is the coauthor of Lojban For Beginners.

Comparison with other auxiliary languages


Loglan is now a generic term that refers both to James Cooke Brown's Loglan, and all languages descended from it. Since the organization that Dr. Brown established, The Loglan Institute (TLI), still calls its language Loglan, it is necessary to state that this section refers specifically to the TLI language, instead of the entire family of languages.

The principal difference between Lojban and Loglan is one of lexicon. A Washington DC splinter group, which later formed The Logical Language Group, LLG, decided in 1986 to remake the entire vocabulary of Loglan in order to evade Dr. Brown's claim of copyright to the language. After a lengthy battle in court, his claim to copyright was ruled invalid. But by then, the new vocabulary was already cemented as a part of the new language, which was called Lojban: A realization of Loglan by its supporters.

The closed set of five-letter words was the first part of the vocabulary to be remade. The words for Lojban were made by the same principles as those for Loglan; that is, candidate forms were chosen according to how many sounds they had in common with their equivalent in some of the most commonly spoken languages on Earth, which was then multiplied by the number of speakers of the languages with which the words had letters in common. The difference with the Lojban remake of the root words was that the weighting was updated to reflect more recent numbers of speakers for the languages. This resulted in word forms that had fewer sounds taken from English, and more sounds taken from Chinese. For instance, the Loglan word norma is equivalent to the Lojban word cnano (cf. Chinese 常, pinyin cháng), both meaning "normal".

Grammatical words were gradually added to Lojban as the grammatical description of the language was made.

Loglan and Lojban still have essentially the same grammars, and most of what is said in the Grammar section above holds true for Loglan as well. Most simple, declarative sentences could be translated word by word between the two languages; but the grammars differ in the details, and in their formal foundations. The grammar of Lojban is defined mostly in the language definition formalism YACC, with a few formal "pre-processing" rules. Loglan also has a machine grammar, but it is not definitive; it is based on a relatively small corpus of sentences that has remained unchanged through the decades, which takes precedence in case of a discrepancy.

There are also many differences in the terminology used in English to talk about the two languages. In his writings, Brown used many terms based on English, Latin and Greek, some of which were already established with a slightly different meaning. On the other hand, the Lojban camp freely borrowed grammatical terms from Lojban itself. For example, what linguists call roots or root words, Loglanists call primitives or prims, and Lojbanists call gismu. The lexeme of Loglan and selma'o of Lojban have nothing to do with the linguistic meaning of lexeme. It is a kind of part of speech, a subdivision of the set of grammatical words, or particles, which loglanists call little words and lojbanists cmavo. Loglan and Lojban have a grammatical construct called metaphor and tanru, respectively; this is not really a metaphor, but a kind of modifier-modificand relationship, similar to that of a noun adjunct and noun. A borrowed word in Loglan is simply called a borrowing; but in English discussions of Lojban, the Lojban word fu'ivla is used. This is probably because in Lojban, unlike Loglan, a certain set of CV templates is reserved for borrowed words.

In the new phonology for Lojban, the consonant q and the vowel w were removed, and the consonant h was replaced by x. The consonant ' (apostrophe) was added with the value of [h] in the International Phonetic Alphabet, but its distribution is such that it can appear only intervocally, and in discussions of the morphology and phonotactics, it is described not as a proper consonant, but a "voiceless glide". (This phoneme is realized as [θ] by some speakers.) A rigid phonotactical system was made for Lojban, but Loglan does not seem to have had such a system.


Lojsk was conceived by Ari Reyes, heavily influenced by Loglan, Lojban, Universal Networking Language (UNL), Esperanto, Visual Basic, Dutton's Speedwords, Ceqli and Guaspi. It is designed to be more single-syllable oriented. If possible, that would nonetheless lead Lojsk to be even more sensitive to noisy environments than Lojban is, therefore its practicability in oral communication may be questioned.


Voksigid, created by an Internet working group led by Bruce R. Gilson, attempts to construct a predicate language of a different type from those which had gone before. Its syntax was somewhat influenced by Japanese, and its vocabulary was based mostly on European language roots. Loglan and Lojban both use word order to mark the various places in the predication, but because remembering which position means which role in the predication might be beyond easy memorization for most people, Voksigid was designed in order to overcome this issue. It uses an extensive set of very semantically specific prepositions to mark the roles of verb arguments, instead of positional order as in Loglan and Lojban.


Guaspi is a descendent of Lojban and Loglan which uses Chinese-like tones to mark grammatical structure, developed by Jim Carter. By using tones instead of structure words, and cutting predicates from two to one syllable, Carter has fixed a minor flaw in Guaspi's predecessors they take a lot of syllables to say things.

Pop Culture Reference

  • XKCD, a popular webcomic, makes reference to this language



  • Goertzel, Ben: Potential Computational Linguistics Resources for Lojban. Self-published, March 6, 2005.
  • Speer, Rob; Havasi, Catherine: Meeting the Computer Halfway: Language Processing in the Artificial Language Lojban. Massachusetts Institute of Technology, 2004.
  • Lojban vs Loglan comparison
  • Lojban with attitude!. Lojban for Beginners. Retrieved on 29 June., 2005.

External links


Personal blogs

Learning courses/resources





Short stories, novellas, and novels

Search another word or see lojbanon Dictionary | Thesaurus |Spanish
Copyright © 2015, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature