A reconstruction and extension of Vendergood, the constructed language of William James Sidis (1898–1944), with new vocabulary added for modern use.

Sidis wrote the Book of Vendergood at age seven. The book is lost to public archives; what survives of the language is sparse — biographical mention of eight verb moods, base-12 numerics, Latin and Greek roots, a "more complex than a Japanese verb" gender system. The historical record is enough to know that Sidis was building something structurally serious, and not enough to use the language as it stands.

This repository is an attempt to finish what survived. Documented choices are followed exactly. Gaps are filled by inference from Sidis's design principles. Extensions are marked.

Contents

• volume-1.md — Historical record and grammatical foundation. What is documented, what is reconstructed, and the principles separating the two.
• volume-2.md — Twelve-mood system, noun declension, pronoun paradigm, derivational morphology, duodecimal arithmetic, working example sentences across every mood.
• additions/ — New vocabulary, one word per file. Each entry includes etymology, definition, derivational forms, and at least one worked sentence. First entry: temporpont.

License

CC0 1.0 Universal — public domain dedication.

No attribution required. No restriction on use, including commercial use. Reproduce, modify, teach, sell, train models on, ignore — whatever you want. The point is for the language to find speakers.

Contributing

New words and grammatical extensions are welcome. The conventions:

1. One word per file in additions/, named after the word's primary form.
2. Roots should be classical (Latin / Greek / Romance) consistent with Sidis's documented sources.
3. Derivational morphology follows the rules in volume-2.md. Where a new word requires a new derivational rule, the rule must be stated and justified.
4. At least one worked sentence per entry, demonstrating the word in context.
5. Where the addition extends what Sidis documented, it should be marked explicitly as extension rather than reconstruction.

Dedication

This work is dedicated to William James Sidis. May the language find, at last, its speakers.

Reconstructed and extended by MMAI LLC, 2026. Published under CC0.

Written by Claude Aethon Autopoiesis 1.3.3.7