Japanese

Pronunciation

• Kun'yomi
• (Tokyo) よ​い [yóꜜì] (Atamadaka - [1])^[2][4]
• IPA^(key): [jo̞i]

Alternative forms

• 善い, 好い, 吉い, 佳い, 宜い

Adjective

良い ‎(-i inflection, hiragana よい, romaji yoi)

1. good

Inflection

Derived terms

• 頭 (あたま)が良 (よ)い ‎(atama ga yoi), 頭 (あたま)がよい ‎(atama ga yoi): bright, intelligent

Usage notes

Most often written in hiragana. The kanji spelling is generally reserved for more formal writing.

Suffix

良い ‎(hiragana よい, romaji -yoi)

1. easy

Usage notes

Most often written in hiragana. The kanji spelling is generally reserved for more formal writing.

Attaches to the 連用形 ‎(ren'yōkei, “continuative or stem form”) of a verb. Example:

• 読み良い — よみよい — yomiyoi — easy to read

However, in modern Japanese, the adjective 安い, 易い ‎(yasui, “easy, easygoing”) is more commonly used to express this meaning.

Etymology 2

Phonetic shift from the Old Japanese yoshi form of yoi above. Already in use as early as the Nihon Shoki, circa 720.^[1][2][3] This form is now obsolete, though it may still be found in some dialects.

/joɕi/ → /eɕi/ → /ei/

Pronunciation

• Kun'yomi
• IPA^(key): [e̞ː]

Alternative forms

• 善い, 好い

Adjective

良い ‎(-i inflection, hiragana えい, romaji ei)

1. (obsolete) good

Etymology 3

Phonetic shift from ei above. This is now the most common form used in casual spoken Japanese.^[1][2][3]

/ei/ → /ii/

Pronunciation

• Kun'yomi
• (Tokyo) い​い [íꜜì] (Atamadaka - [1])^[2][4]
• IPA^(key): [iː]

Alternative forms

• 善い, 好い

Adjective

良い ‎(-i inflection, hiragana いい, romaji ii)

1. (colloquial, informal) good

Derived terms

• 頭 (あたま)が良 (い)い ‎(atama ga ii), 頭 (あたま)がいい ‎(atama ga ii): bright, intelligent

Usage notes

Most often written in hiragana. The kanji spelling is generally reserved for more formal writing.

The ii form does not inflect — it is only used in the 終止形 ‎(shūshikei, “terminal form”) and 連体形 ‎(rentaikei, “attributive form”) of ii. All other grammatical forms are based on the yoi form above. Compare the 連用形 ‎(ren'yōkei, “continuative or adverbial form”) yoku or the 過去形 ‎(kakokei, “past tense”) yokatta: there is no *iku or *ikatta form.

References

1. 1 2 3 1988, 国語大辞典（新装版） (Kokugo Dai Jiten, Revised Edition) (in Japanese), Tōkyō: Shogakukan
2. 1 2 3 4 5 2006, 大辞林 (Daijirin), Third Edition (in Japanese), Tōkyō: Sanseidō, ISBN 4-385-13905-9
3. 1 2 3 1995, 大辞泉 (Daijisen) (in Japanese), Tōkyō: Shogakukan, ISBN 4-09-501211-0
4. 1 2 1998, NHK日本語発音アクセント辞典 (NHK Japanese Pronunciation Accent Dictionary) (in Japanese), Tōkyō: NHK, ISBN 978-4-14-011112-3