Japanese first. Built for more languages later.

Learn Japanese with structure, sound, and context.

Word Sky is the home of Kotoba, a language learning platform for English speakers learning Japanese. Study writing systems, verb forms, vocabulary, grammar, and real practice items in one calm workspace.

Open KotobaExplore features

Kana and kanji study

Conjugation tables

Image-based practice

Teacher-authored content

Everything starts with language structure.

Kotoba is designed around the shape of Japanese: writing systems, verb classes, readings, grammar roles, and authored practice.

Move from hiragana and katakana into kanji with readings, meanings, examples, and optional audio all kept together.

Kotoba

Kana and kanji explorer

Structured language data keeps pronunciation, grammar, examples, and learner practice connected.

あ a

カ ka

日 nichi / hi

語 go

A platform for learning, authoring, and expanding.

Word Sky balances beginner clarity with the structured data teachers need to keep lessons accurate over time.

For new learners

Sound things out before you are ready to read everything.

Romaji hints, readings, kana grids, and English context help beginners connect what they see to what they hear.

Word Sky

Beginner-friendly scaffolding

romaji hints
readings stored separately
native IME ready

For teachers

Publish clean content instead of patching learner screens later.

Admin tools separate drafts from published lessons and preserve manual corrections during regeneration.

Word Sky

Authoring controls

draft, review, published, archived
override-safe merges
audio uploads

For language growth

Japanese is the first course, not the hardcoded ceiling.

Languages, scripts, POS tags, and language pairs live in data so Word Sky can grow beyond one course architecture.

Word Sky

Language-agnostic foundation

language pairs
script records
database POS taxonomy

Start learning in the live app

Kotoba is already deployed at app.word-sky.com. Sign in with a magic link and explore the first Japanese learning foundation.

Open Kotoba

Built for the moments that make language stick.

Word Sky gives learners enough support to keep moving and gives teachers enough structure to keep content accurate.

    • A new learner can start with kana, romaji hints, and clear English context instead of being dropped into a wall of unfamiliar symbols.

      Beginner study
      Sound, script, and meaning together

    • A returning student can compare verb forms side by side and see how generated conjugations relate to authored examples.

      Grammar review
      Conjugations without guesswork

    • A teacher can review generated forms, correct exceptions, and publish content without worrying that regeneration will erase their work.

      Teacher workflow
      Override-safe authoring

    • Practice items can combine an image, Japanese line, English line, readings, romaji, and POS annotations for more grounded study.

      Context practice
      Language inside a scene

    • The database treats languages, scripts, and grammar taxonomies as content, which gives Word Sky room to support more courses later.

      Course expansion
      Data-driven language support

    • Learner-facing pages only query published content, keeping drafts and review material out of the study experience by default.

      Publishing safety
      Centralized content guards

Start small, grow into a language platform.

Word Sky is in its production-foundation phase. The learner app is live now, with teacher and course expansion workflows growing from the same architecture.

Learner

For students exploring Japanese through structured, beginner-friendly study.

Live

  • Magic-link sign in
  • Personal flashcards
  • Kana and kanji study
  • Conjugation tables
  • Practice items with hints
Learn more

Kotoba beta

The current app foundation for evaluating the full learning workflow.

Open

  • Japanese course foundation
  • Published-content safeguards
  • Romaji and reading support
  • POS-highlighted sentences
  • Cloudflare-native deployment
  • Teacher-ready data model
  • Future language-pair support
Open app

Teacher tools

For authored courses, review workflows, and richer classroom operations.

Next

  • Verb and character authoring
  • Manual override review
  • Audio upload workflows
  • Practice item management
  • Learner account controls
Learn more

Frequently asked questions

A few clear answers about the app, the architecture, and where Word Sky is heading next.

    • What is Word Sky?

      Word Sky is the public home for Kotoba, a web-based language learning platform currently focused on English speakers learning Japanese.

    • Is the app live?

      Yes. The Kotoba app is deployed at app.word-sky.com with magic-link sign in, learner study surfaces, admin authoring foundations, and seeded Japanese content.

    • Why start with Japanese?

      Japanese gives the platform a serious first test: multiple scripts, readings, conjugation rules, POS analysis, and context-rich practice.

    • Does Word Sky only support Japanese?

      Japanese is the first course, but the architecture stores languages, scripts, language pairs, and POS taxonomy as data so future courses do not require a schema rewrite.

    • How do beginners handle pronunciation?

      Romaji and readings can be stored alongside Japanese text, so new students can connect sounds to kana and kanji while they build confidence.

    • Are grammar highlights generated live?

      No. POS analysis happens at author time. Learners see precomputed annotations, which keeps study pages fast and predictable.

    • Can teachers edit generated conjugations?

      Yes. The conjugation engine supports manual overrides, and regeneration preserves teacher corrections instead of overwriting them.

    • Is this an AI-generated course?

      No. Phase 1 is built around teacher-authored content, deterministic language logic, and explicit reviewable data.

    • What is next?

      The next wave is polish, richer learner evaluation, course content depth, and a marketing site deployment for word-sky.com.