First opened Sunday, February 4, 2007
良い
よい
- head-high (atamadaka): falls after mora 1
How to read it: a line over a kana means the voice is high there, and ↓ marks where it drops. A kana with no line is low. With no ↓ the pitch stays high to the end and does not drop even on a following particle (が, は).
good, nice
Yoi is the modern form of the Old Japanese adjective よし (yoshi).
Taken apart
No breakdown is shown for this word: Wiktionary's text for it doesn't give a split that spells the word and joins to its reading, and any other split would be a guess.
Written with 良
In a sentence
よい週末を！
Have a good weekend!
よい質問だ。
Good question!
Sentences are from Tatoeba (CC BY 2.0 FR), picked by fixed rules from a dated export and shown unchanged. Nobody has reviewed them one by one.
What Wiktionary says
Quoted line by line from Wiktionary's Etymology section for this reading, taken from one dated dump so it can't change underneath us. Nothing below is paraphrased.
- “Modern form of Old Japanese adjective よし (yoshi).”
- “/joɕi/ (classical 終止形 (shūshikei) or terminal form) → /joki/ (classical 連体形 (rentaikei) or attributive form) → /joi/ (modern shūshikei and rentaikei)”
Source: Wiktionary: 良い (dump of 2026-09-02), available under CC BY-SA 4.0. Reading, meaning and part of speech from JMdict, and kanji readings from KANJIDIC2 (EDRDG).
Other readings of 良い on the same Wiktionary page
These describe other words written the same way, not よい. They are quoted for context: the parts, layer and processes of this word are not taken from them.
えい
- “Phonetic shift from the Old Japanese yoshi form of yoi above. Already in use as early as the Nihon Shoki, circa 720, then becoming common in eastern Japanese from the Edo period. This form is now obsolete, though it may still be found in some dialects.”
- “/joɕi/ (classical 終止形 (shūshikei) or terminal form) → /eɕi/ (classical 終止形 (shūshikei) or terminal form) → /eki/ (classical 連体形 (rentaikei) or attributive form) → /ei/ (modern shūshikei and rentaikei)”
いい
- “Phonetic shift from ei above. This is now the most common form used in casual spoken Japanese.”
- “/ei/ → /ii/”
What the labels mean
- 和語 Native Japanese
- Words that were already Japanese before Chinese vocabulary arrived — usually written with kun'yomi and often short.
- Sound change
- The pronunciation shifted over the centuries.