🗣️Lojban

1. What Lojban is — and what it is not

Lojban (la .lojban.) is a constructed language of the logical or engineered type. Its grammar is built on rules derived from predicate logic, and it is designed to be syntactically unambiguous and machine-parsable: a well-formed sentence has exactly one grammatical structure.¹⁴ It is not a naturalistic language and was not designed to imitate any existing one.¹ Confidence: High.

It is catalogued by Glottolog under lojb1234 and holds ISO 639-3 code jbo, so text can be tagged lang="jbo" for software.²³ The language is documented and promoted by the Logical Language Group (LLG, la lojban), a non-profit founded in 1987 to study the relationships between language, thought and logic.⁴ Confidence: High.

Lojban descends from Loglan, a project begun by sociologist James Cooke Brown in the 1950s. Following a dispute over control of Loglan, the LLG began a separate, rebuilt version in 1987 with its own vocabulary; that version is Lojban.⁴ Its central reference grammar, The Complete Lojban Language by John Woldemar Cowan, was published in 1997.¹ Confidence: High.

2. Writing system and orthography

Lojban is written in the Latin alphabet and its spelling is phonemic — each letter stands for one sound. The letters used are the six vowels a e i o u y and the consonants b c d f g j k l m n p r s t v x z, plus three special characters: the apostrophe (’), the period (.) and the comma (,).⁵ Capitalisation is not grammatically meaningful and is normally used only to mark irregular stress in names.¹ Confidence: High.

The apostrophe ’ represents an unvoiced [h] between vowels; the period . marks a glottal stop or a mandatory pause; the comma , is a rarely used syllable separator.⁵ Confidence: High.

3. Pronunciation: the sounds of Lojban

The Complete Lojban Language defines each letter's pronunciation with the International Phonetic Alphabet, allowing some variation between speakers. Five of the six letters that are hardest for English speakers are c, j, x, y and the rhotic r.⁵ Confidence: High.

The two English affricates 'ch' and 'j-as-in-judge' are not single Lojban sounds; they are written as two consonants, tc ([tʃ]) and dj ([dʒ]).⁵ Word stress falls on the next-to-last syllable of most words, as described in the reference grammar's chapter on syllabication and stress.¹ Confidence: High for the consonant values; Medium-High for the stress rule, which is stated in CLL §3.9 but not re-derived here.

4. How a sentence is built: bridi, selbri, sumti

The core unit of Lojban is the bridi — a predicate relationship. A bridi is made of one selbri (the relation, roughly a verb/adjective/noun rolled together) and one or more sumti (the arguments that fill the relation's numbered places).¹ Each selbri comes with a fixed place structure that says what goes in place x1, x2, x3 and so on. Confidence: High.

For example, the root nelci means 'x1 likes x2', and patfu means 'x1 is a father of x2'. Fill the places with sumti such as mi ('I/me') and do ('you'):⁴ Confidence: High.

All four sentences are attested on the official Lojban wiki.⁴ Notice that the question word ma simply stands in the place whose value you are asking about — Lojban does not reorder the sentence to form a question.⁴ Confidence: High.

5. Word classes: gismu, cmavo, and compounds

Lojban content words divide into a few well-defined classes. gismu are the roughly 1,300 five-letter root words. cmavo are short structure words (particles) that do grammatical work. lujvo are compounds built from gismu roots, and a tanru is a phrase in which one word modifies another. Names are cmene, and borrowed words are fu'ivla.¹ These categories are defined in chapter 4 of the reference grammar. Confidence: High.

6. Attitudinals and what is optional

Lojban marks emotion with a special class of words called attitudinals, which act like spoken emoticons: .ue marks surprise, ba'u marks exaggeration, and so on.⁴ Marking of tense (past/present/future) and of number (singular/plural) is optional and left out when context makes it clear.⁴ Confidence: High.

7. A small set of attested words

This is an orientation, not a dictionary. The words below are limited to items directly attested in the sources reviewed for this guide. For a full lexicon, use the community dictionaries linked in section 9.⁴ Confidence: High.

8. Common learner cautions

The single biggest adjustment for beginners is that every selbri carries a fixed place structure that must be learned together with the word — knowing that nelci means 'like' is not enough; you must know that the liker is x1 and the thing liked is x2.¹ Beginners should also take care with the special letters (c, j, x) and with the period and apostrophe, since these are true parts of spelling and pronunciation, not decoration.⁵ Confidence: High.

9. Resources and where to learn

• The Complete Lojban Language (CLL)Reference — John Cowan's 1997 reference grammar published by the Logical Language Group — the authoritative description of the language. Best as a reference once you know some Lojban.
• lojban.org — the Logical Language GroupAll levels — Official site and community wiki: news, learning links, and community contacts.
• la sutysisku — dictionaryAll levels — Searchable multilingual Lojban dictionary that also works offline.
• la jbovlaste — collaborative dictionaryAll levels — Editable multilingual dictionary regarded by many as the de-facto standard word source.
• la kardaBeginner — A rapid-fire overview of the grammar in small pieces — a community-made learning aid.
• Lojban Wave LessonsBeginner — A popular community textbook. Unofficial and represents its authors' views.

Honest limitations

This is an orientation, not a course. It is compiled from the reference grammar, the official wiki, and catalogue records rather than from a full teaching curriculum. The vocabulary table is deliberately small and restricted to words attested in the sources cited; any expanded word list or sentence-teaching material should be taken from The Complete Lojban Language and the community dictionaries, which are the canonical authorities. No downloadable flashcard deck is provided in this version. Lojban has a community flag (the ‘la lojban’ banner), but no verified flag file was available for this build, so the page shows the neutral marker rather than an unverified image. The Complete Lojban Language is copyright the Logical Language Group; this guide restates factual descriptions in its own words and does not reproduce its text or tables.