The Khæn language is often informally called Khænish by outsiders. The name's actual literal translation is 'communication [for] bipedal predators'. It is generally considered an analytic language, having no inflexion and adhering to an invariant two-morpheme word structure. About 150 million people speak the Khæn language.
The Khæn language is the most ancient living language on Etéra, and also paradoxically the most unchanging one. Etéra's first confirmed history records are written in Khænish. However, the more obscure history of the language dates even further back - there are multiple copies of large libraries of stone tablets buried throughout the Islands, and those contain a concise dictionary, descriptions of how syntax works, and other rules of the language, as well as a description of the Khænish calendar. Both the tablets and the start of the calendar date a bit over 50 thousand Etéran years into the past (over 13 million days). There are no other signs of civilisation dating this far back - just standalone buildings or dugouts with stone-reinforced walls containing large stacks of thin tablets with alchemically etched writing on them.
The language has been relatively stable, with the Khæn doing their best to conform to the ancient guidelines. Most notably, there are rules for coining new compound word-groups in a way that produces relatively little ambiguity, and was shown to cause convergent evolution of vocabularies even if isolated groups of people are exposed to the same yet-unnamed things or events. For example, the word-group for a spaceship is unambiguously derived from ancient guidelines on how to classify or describe something that is not a bird but flies, is crafted by the people for the people, and can move in a certain manner.
Khæn writing uses cuneiform-like strokes (literally called 'claw-marks') to create either syllabic-phonetic or ideographic symbols as necessary, going left-to-right. Syllabic symbols have a base form (which denotes one consonant and one vowel or vice versa) and modified forms (which add more consonants to the beginning of an initial syllable or the end of a closing syllable). The syllabic writing system is orthographically shallow, while the ideographic one, by contrast, lacks a link between orthography and phonology whatsoever.
Khæn language has a rich phonetic inventory.
All Khæn words consist of two morphemes, represented by an opening (initial) syllable and a closing (final) syllable. Word-groups are used where two morphemes are insufficient to convey the necessary meaning of a noun or verb. Initial syllables always start with one or more consonants and end in a vowel, while final ones always start with a vowel and end in one or more consonants. It is common but not obligatory for the two colliding vowels to turn into a diphthong, like in the word Khæn.
There is no inflexion in words whatsoever - no case, no gender, no tense.
Khæn has a flexible word order, aided by use of service words which denote relations between parts of the sentence. Syntactic structures change somewhat depending on the level of formality, urgency of a situation etc.