church-translate/docs/PLAN-spanish-variants.md

Plan — three Spanish variants for live preaching

The ask

Operator, relaying a native Spanish speaker: the Spanish output is Latin American, and three variants are wanted — Latin American, Spain, Mexican — "fine tuned exactly to how it's supposed to be". No native speaker will be provided; research from the web instead. Nothing may be left out.

Finding 1 — the taxonomy overlaps

es-MX is INSIDE es-419, not beside it. Their differences are lexical only (computadora/ordenador, carro/coche, ícono/icono). es-ES is the one that differs GRAMMATICALLY. So the three deliverables are not three equal problems:

variant	differs from es-419 by	difficulty
es_419 Latin American	— (this is today's output)	none
es_MX Mexican	word choice	low, deterministic
es_ES Spain	the whole 2nd-person-plural system	high

Reference editions, so each variant has an authority rather than my preference:

• es_ES → Reina-Valera 1960 (uses vosotros) / LBLA
• es_419 → NBLA (explicitly uses ustedes for Latin America) / NVI
• es_MX → NBLA + Mexican lexicon

Finding 2 — why es-ES cannot be a find-and-replace

Spanish 3rd-person-plural is IDENTICAL for "ustedes" (you all) and "ellos" (they). hablan is both. So a target-side rule hablan → habláis corrupts every genuine third-person sentence: "they were there" becomes "you all were there". In scripture. Silently. This is the exact failure class the whole fidelity effort exists to prevent, so a naive transform is not shippable.

Finding 3 — the English source resolves the ambiguity

This is the key idea and it may remove the need for any model change.

The ambiguity is unresolvable in the Spanish. It is already resolved in the ENGLISH, which we still have:

"Open YOUR Bibles."        -> 2nd person -> ustedes-form -> convert
"THEY were there."         -> 3rd person -> ellos-form   -> leave alone

So: convert to vosotros ONLY when the English sentence contains 2nd-person address AND contains NO 3rd-person-plural marker. Mixed sentences ("tell them that you are loved") are left in es-419 form — which a Spaniard understands perfectly, it just reads Latin American. Conservative by construction: the failure mode is "not converted", never "wrongly converted".

Design

NLLB -> guard -> cache -> [es-419 base]
                             |-- es_MX : lexical layer
                             |-- es_ES : gated vosotros transform
                             `-- es_419: as-is

Same shape as pt-variants.js (por_Latn / por_PT share one NLLB result), and it reuses NLLB_ALIAS so the extra variants cost no extra inference.

New pseudo-codes spa_MX and spa_ES, both aliased to spa_Latn at the MT boundary only — exactly how por_PT already works.

es_ES transform components

1. Gate (on the English source): 2nd-person markers present, 3rd-person-plural markers absent.
2. Pronouns/possessives: ustedes→vosotros, su(s)→vuestro(s)/vuestra(s), les→os, se (reflexive 2pl)→os, a ustedes→a vosotros.
3. Verb morphology: 3pl→2pl. -an→-áis; -en→-éis for -er verbs but -en→-ís for -ir verbs, so the verb's class must be known — a table, not a rule. Irregulars (ser, ir, tener, hacer, poder, querer, decir, venir, saber, dar, ver, poner, salir, traer, oír, haber) need explicit entries.
4. Imperatives: abran→abrid, vengan→venid, miren→mirad — highest frequency in preaching and the most audible difference.

es_MX layer

Lexical only. Word-level, no morphology, no gate needed.

What must not regress

• Latency: no extra inference. All layers are string work over a shared result.
• applyOverrides still runs last so an operator pin outranks everything.
• The English caption and archive keep what was actually said.
• Voice: speech-text.js has Spanish book-name rules (ES_BOOKS) that fire on 1 Corintios → Primera de Corintios. New variants must not produce forms outside that list or the voice reads "uno Juan".
• Each variant needs its own voice choice — es_ES should get a Castilian voice (miro/sharvard, measured male), es_MX the Mexican ald.

Open questions for the audit

1. Is the source-side gate actually safe? Where does it misfire?
2. Verb-table coverage: what fraction of real sermon Spanish is reachable?
3. Does adding two pseudo-languages break the shared-cache invariant?
4. Is vosotros even wanted? RVR1960 uses it and is read across Latin America.
5. Does the listener page cope with three Spanish entries in the picker?