Historical Kana (旧仮名遣い) in Japanese Classics: A Reader's Survival Guide
October 13, 2026
Why Old Kana Spellings Exist
If you have opened an Aozora Bunko text and seen 言ふ where you expected 言う, or ゐる where you expected いる, you have met historical kana spelling, usually called 歴史的仮名遣い or 旧仮名遣い.
It was the general spelling standard before the 1946 adoption of 現代かなづかい. The modern system writes contemporary Japanese mainly according to its pronunciation, while retaining some spelling conventions. Japan's Agency for Cultural Affairs provides an official comparison table.
Spelling is not the same as grammar
Changing 言ふ to 言う helps you recognize the word. It does not automatically turn a passage into modern Japanese. Older texts can also contain unfamiliar vocabulary and classical conjugations. Treat the patterns below as reading aids, not a complete translation algorithm.
Where you will encounter it
- Some Aozora Bunko editions of prewar literature
- Prewar newspaper reprints and historical documents
- Some later works that retain historical spelling
Check the edition rather than assuming that every older work preserves its original spelling.
The Core Conversion Patterns
These five patterns give you a useful starting point. They are not instructions to replace every matching character in a text.
Pattern 1: Some verb endings written ふ correspond to modern う
Common examples include:
| Historical spelling | Modern spelling | Meaning |
|---|---|---|
| 言ふ | 言う | to say |
| 思ふ | 思う | to think |
| 買ふ | 買う | to buy |
| 笑ふ | 笑う | to laugh |
Related forms include 言ひ → 言い and 言へ → 言え. Identify the word and its grammatical form first: this is not a rule that every ふ, wherever it appears, becomes う.
Pattern 2: ゐ and ゑ correspond to modern い and え
For modern reading, historical ゐ and ゑ usually correspond to い and え.
- ゐる → いる: to be or exist, as in 居る
- ゑ → え
Do not infer how people pronounced a word in a particular historical period from its modern reading alone. Historical sound changes and historical spelling are related but different questions. Proper names may also retain older written forms.
Pattern 3: Lexical を corresponds to modern お
Historical を can appear within a word, not just as the object particle.
- をとこ → おとこ: man
- をんな → おんな: woman
- をかし → おかし: a classical adjective meaning charming or interesting, not the modern noun お菓子
The object particle remains written を in modern spelling. Context tells you whether you are looking at a word or a particle.
Pattern 4: Some internal は-row spellings reflect older sounds
In words affected by the historical sound change called は行転呼, older は-row spellings can correspond to modern わ, い, う, え or お.
- かは → かわ: river
- うへ → うえ: above
- おほい → おおい: many
These are correspondences in particular words, not blanket substitutions for every は-row kana inside a word. The particles は and へ retain those spellings in modern Japanese.
Pattern 5: ぢ and づ sometimes correspond to じ and ず
Historical spellings such as みづ correspond to modern みず. But modern spelling still requires ぢ or づ in some words:
- 鼻血: はなぢ, not はなじ
- 続く: つづく
- 縮む: ちぢむ
The official modern spelling rules explain these retained forms. If a historical form fails a dictionary search, trying じ or ず can help, but check the entry before adopting that spelling.
One more trap: whole vowel sequences
Some changes involve a sequence rather than one character. For example, けふ corresponds to きょう, and てふ to ちょう. A character-by-character ふ → う substitution would not produce the modern reading. The official comparison tables are useful when a form does not fit the simpler patterns.
Putting the Patterns to Work
Here is an original practice example, not a quotation from a published story:
Historical-style spelling: ゆつくり歩いてゐる。
>
Modern spelling: ゆっくり歩いている。
>
Meaning: Walking slowly.
Two separate changes make the sentence easier to recognize:
- ゐる → いる follows the ゐ correspondence.
- In this word, ゆつくり corresponds to modern ゆっくり: the written つ represents the sound now written っ.
In other words, you may also see や, ゆ or よ where modern text has ゃ, ゅ or ょ. Check the word and reading rather than replacing every matching character.
A quick-reference card
- Identify the word before changing its spelling.
- Recognize common forms such as 言ふ → 言う and ゐる → いる.
- Distinguish lexical を from the particle を.
- Check は-row correspondences rather than replacing characters blindly.
- Keep modern exceptions such as はなぢ and つづく.
- Check whole sequences such as けふ → きょう.
- Separate spelling changes from unfamiliar grammar or vocabulary.
Using tools alongside the patterns
Keep a dictionary and the official comparison table nearby. If a historical spelling is not found, try a likely modern form and compare its meaning with the sentence. For passages available in iroiro reader, contextual definitions are available on tap.
Start with one short passage. The goal is not to memorize every spelling change at once, but to recognize recurring forms without losing track of what the sentence says.