The Roots of Japanese¶
Learn Japanese vocabulary the way English speakers learn from Latin roots: by the building blocks, not one word at a time.
The idea¶
In English, one Latin or Greek root unlocks a whole family of words:
| Root | Meaning | Words it unlocks |
|---|---|---|
| struct | build | construct, structure, instruct, infrastructure, obstruction |
| port | carry | import, export, transport, support, portable |
Japanese works the same way. A single kanji is a root that combines with other kanji to generate families of compound words. Learn the root, and you can read (and eventually guess) compounds you have never seen before.
| Kanji root | Like | Unlocks |
|---|---|---|
| 不 (not) | un-, in-, dis- | 不安, 不便, 不可能, 不満, 不正 |
| 者 (person) | -er, -ist | 医者, 科学者, 記者, 読者, 労働者 |
| 生 (life) | bio-, -genesis | 生活, 生産, 生命, 学生, 先生 |
Why this exists¶
The usual way to study is one kanji, then one compound, then another, like memorizing construct, instruct, and structure without ever noticing they share struct. Every word becomes a separate task.
This project reverse-engineers the system instead. It finds the most productive kanji (the ones that appear in the most compound words) and maps how they behave: which position they prefer, how many words they unlock, and which English root they mirror.
The two systems¶
- Kanji roots (nouns and concepts) - one kanji plus many partners makes many compound words. Like Latin and Greek roots.
- Verb roots (actions and aspects) - one verb core plus many "particle" verbs makes many nuanced actions. Like English phrasal verbs (give up / give in / give out).
Start here¶
- Kanji Roots: Catalog - browsable families of the most productive kanji, each mapped to its English-root analogy.
- Kanji Roots: The Data - the numbers behind the catalog: productivity counts and left/right position analysis from a 27,950-compound database.
- Kanji Roots: Sound Roots - the phonetic part inside each character: learn one sound, predict many readings.
- Verb Roots - how Japanese verbs combine, from the polymorphic 〜込む to bases like 取り〜.
New to the idea? Read in order. Want a reference? Jump straight to the Catalog.
Sources¶
All productivity numbers on this site come from one dataset, for consistency:
- Tamaoka et al. (2017) - kanjidatabase.com (2,136 Jōyō kanji, 27,950 two-kanji compounds from an 11-year newspaper corpus). The source of every number here.
- Tamaoka & Altmann (2004) - the foundational study on kanji productivity, cited for historical context.
- NINJAL Compound Verb Lexicon - vvlexicon.ninjal.ac.jp (2,700+ compound verbs).
- NINJAL Basic Verb Handbook - www2.ninjal.ac.jp/verbhandbook (190 polysemous verbs).