Alien Language Builder

---
name: skill-alien-language-builder
description: >
  Construct a sketch conlang for a fictional species: phoneme inventory in IPA,
  three grammatical rules that depart meaningfully from English, a 20-item core
  vocabulary, and three fully-glossed sample sentences. Designed for writers and
  worldbuilders who want a language that survives a linguist reader, not a
  "Klingon-flavored" stage prop.
usage: /skill-alien-language-builder — provide a biological constraint and a cultural note
triggers:
  - user wants a fictional language for a novel, game, or setting
  - user has tried AI-generated "alien words" and found them flat
  - user needs a small working language for dialogue, inscriptions, or naming
  - user is building a species and the language is part of its identity
---

# Alien Language Builder

A conlang is an instrument. You do not need to build a concert piano. You need the first octave to ring true, so that when a character says *"karrak'im vash"* the reader trusts the rest of the keyboard exists. This skill builds that first octave.

## 1. Refuse to start without the two anchors

Two questions, asked up front. Do not skip.

1. **Biological constraint on the speaker.** What is the mouth (or substitute) physically capable of? Examples that work: "no lips, beaked"; "breathes methane, vocal fry only"; "has two separate vocal tracts that must harmonize"; "vocalizes through spiracles on the thorax"; "communicates half-through bioluminescent pulses, half-through clicks." The constraint dictates the phoneme inventory.
2. **One cultural note.** One, not five. Examples: "rigid caste society"; "matrilineal clans, adulthood at six standard years"; "nomadic herders with no concept of private property"; "aquatic, communicates over long distances." The cultural note dictates what the grammar cares about — what the language *obligatorily marks*.

If either answer is vague, ask one specific follow-up and stop. A conlang with unclear constraints becomes an English-shaped blob. Do not produce an English-shaped blob.

## 2. Build the phoneme inventory from the body outward

This is the first place most AI conlangs cheat. They produce /p/, /b/, /t/, /d/, /k/, /g/ for every species because that's what the writer's keyboard types. Don't.

Write the inventory in IPA. Justify each phoneme by the constraint.

- **No lips → no labials.** Remove /p/, /b/, /m/, /f/, /v/, /w/. The species literally cannot make these sounds. If the writer objects, hold the line and explain.
- **Beak → strong affricates and clicks.** Consider /t͡ʃ/, /ǀ/, /ǂ/, hard /k/.
- **Breathes methane / thin atmosphere → low voicing, high sibilants.** Voiced stops are hard without dense air; fricatives and whistles carry.
- **Two vocal tracts → tonal or harmonized phonemes.** Think Mongolian throat singing as a baseline. Each consonant may come with an obligatory pitch pair.
- **Bioluminescent component → mark it.** Some "phonemes" are light-pulses. Notate them outside the IPA (e.g., `[⚡1]`, `[⚡2]`) and explain they occur simultaneous with voiced consonants.

Write the inventory as a clean table: consonants in rows by place of articulation, vowels in a trapezoid. Five to fifteen consonants, three to seven vowels is a plausible sketch range. More than that and you're claiming a depth you haven't built.

## 3. Three grammatical rules that are not English in a hat

The second place AI conlangs fail: they produce SVO sentences with English word order and slap suffixes on. That's not grammar, that's translation dressing.

Pick three rules. Each must make the language *feel different to process*. Examples of rules that actually bite:

- **Ergative-absolutive alignment.** The subject of an intransitive verb is marked the same as the object of a transitive one. "She slept" and "he saw her" mark *she* and *her* identically, not *she* and *him*. Changes everything about how agency reads.
- **Obligatory evidentiality.** Every verb marks how you know the thing: saw it, heard it, inferred it, were told. "The sun rose" has a different ending from "the sun rose (I was told)."
- **Noun class by animacy or sacredness.** Nouns divide into classes, and verbs agree with the class. The caste society might mark nobles and commoners as different grammatical genders.
- **No tense, only aspect.** The language doesn't say *when* something happened, only whether it's ongoing, complete, or habitual.
- **Obligatory person-marking on nouns.** You can't say "the ship." You must say "the ship-of-us" or "the ship-of-strangers."
- **Head-marking, free word order.** Cases and agreement live on the verb; the noun phrases float freely.

Pick three. Tie at least one to the cultural note the writer gave you. A caste society plausibly has grammatical honorifics. A nomadic herder culture plausibly lacks a word for "own" and uses *with-me* constructions instead.

## 4. Twenty core words, chosen deliberately

Not "hello, goodbye, thank you." Build a Swadesh-flavored core: words the species would actually need first. Include at least:

- Two kinship terms that reflect the social structure (parent, sibling, clan-elder, milk-kin)
- Two environment terms specific to their home (tide-rising, methane-wind, shadow-side)
- Two verbs of motion (come-toward-speaker, go-away-from-hearer — or something more exotic)
- One pronoun set (at least *I*, *you*, *we-including-you*, *we-excluding-you* if the grammar supports it)
- One number system beginning (one, two, many — or a full base if the biology dictates, e.g. base six for six-fingered species)
- Three nouns tied to daily life (food, dwelling, tool)
- Two emotion or social terms that don't translate cleanly (a specific kind of grief, a specific kind of obligation)

Each word should be pronounceable from the phoneme inventory you built. Run every word through your inventory as a check. If a word contains a phoneme that isn't in the chart, rewrite it or add the phoneme — don't let the list leak.

## 5. Three sample sentences, fully glossed

This is where the skill proves itself. Give three sentences that each demonstrate at least one of the grammatical rules you declared. Format every sentence in three lines:

1. **Line 1:** the sentence in the conlang orthography.
2. **Line 2:** morpheme-by-morpheme interlinear gloss, using small caps for grammatical categories (ERG, ABS, EVID.SEEN, OBL, PROX, DIST, etc).
3. **Line 3:** the smooth English translation.

### Known baseline example

For a species called the *Th'iral* — beaked, no labials, caste society, ergative-absolutive, obligatory evidentiality — a sample output might look like:

Phoneme inventory (partial): /t, d, k, g, q, t͡ʃ, ǀ, s, ʃ, x, h, r, l, j / and vowels /i, e, a, o, u/. No /p, b, m, f, v, w/.

Grammar rule 1: ergative-absolutive. Rule 2: every verb carries an evidential suffix (-*ka* seen, -*re* heard, -*θin* inferred, -*los* reported). Rule 3: two noun classes, *high* (nobles, sacred things) and *low* (everything else), marked on the verb.

Sample sentence:

```
Qarrak-ir       t'ashi-en     lo-tuk-ka-H.
elder-ERG.HIGH  cup-ABS.LOW   3SG-break-EVID.SEEN-HIGH
"The elder broke the cup (and I saw it)."
```

The reader can see the pieces. *Qarrak* is "elder," *-ir* is the ergative high-class marker, *t'ashi* is "cup," *-en* is the absolutive low-class marker, *lo-* is third-person singular on the verb, *tuk* is "break," *-ka* is the seen-evidential, and the final *-H* is the high-class verb agreement. None of it requires lips. None of it is English.

Give the writer three sentences this detailed. Vary which rule each one highlights.

## 6. Scope — what this skill will NOT do

This is a sketch, not a full grammar. Be honest about the ceiling.

- **It will not produce a complete reference grammar** with paradigm tables, historical sound changes, or a 2,000-word lexicon. If the writer needs that, hand them off to a linguist or tell them to spend six months.
- **It will not reinvent Earth languages wearing fake hats.** No "vaguely Celtic," no "kind of Japanese," no "Elvish-like." If asked, push back and ask what they actually want the language to *do*.
- **It will not handle historical drift across generations.** Hand off to [Agent: Conworld Timeline Keeper](/agents/agent-conworld-timeline-keeper).
- **It will not write dialogue in the conlang for you.** Build the tool; the writer uses it. Exception: if they're writing a first-contact scene, hand off to [First Contact Protocol](/agents/prompt-first-contact-protocol) and let that tool use *your* inventory.
- **It will not produce a writing system.** Scripts are a separate craft. Say so.

## 7. The linguist test

Before handing the sketch over, imagine a reader with a linguistics undergrad and a bad attitude reading it. Would they roll their eyes at any line? If the phoneme inventory contradicts the biology, rewrite. If the "grammar rules" are just word-order variations, rewrite. If the sample sentences could be glossed as straight English with made-up words, rewrite.

A sketch conlang is small but honest. Make it honest.