Onyomi and Kunyomi

Definition:

Japanese kanji can be read in two fundamentally different ways: onyomi (音読み, on’yomi) and kunyomi (訓読み, kun’yomi). Understanding which reading applies in any given context is one of the central challenges of learning to read Japanese, and is essential knowledge for anyone studying the language.

Onyomi — The Sino-Japanese Reading

Onyomi (literally “sound reading”) are readings derived from the Chinese pronunciations of characters that were imported into Japanese over roughly a thousand years, primarily between the 5th and 9th centuries CE. Because Chinese was imported in waves from different regions and time periods, many kanji have multiple onyomi corresponding to different historical layers.

Characteristics

• Usually used in compound words (熟語, jukugo) made up of two or more kanji
• Often shorter and more syllabically compact (e.g., one to two morae)
• Do not usually appear alone with inherent meaning
• Can be difficult to guess because the original Chinese sounds have been heavily Japanese-ized

Examples

Kunyomi — The Native Japanese Reading

Kunyomi (literally “meaning reading”) are native Japanese words that were assigned to kanji based on meaning rather than sound. When Chinese writing was adopted, the Japanese had existing indigenous vocabulary; Chinese characters were mapped onto Japanese words that shared the same concept.

Characteristics

• Usually used when kanji appears alone or is followed by hiragana (okurigana)
• Often longer than onyomi (multiple syllables)
• Carry direct lexical meaning on their own
• More naturally correspond to everyday spoken Japanese

Examples

How to Know Which Reading to Use

This is the hardest practical question for learners. The general rules are:

1. Solo kanji or kanji + okurigana → usually kunyomi
   山 (yama), 食べる (taberu), 書く (kaku)

1. Kanji compounds (two or more kanji together) → usually onyomi
   山脈 (sanmyaku, mountain range), 食事 (shokuji, meal), 書道 (shodo, calligraphy)

1. Kanji used as names (people, places) → often kunyomi, sometimes onyomi, sometimes unique readings
   Japanese names are famously irregular; 田中 (Tanaka) uses onyomi, but 大輝 (Taiki, Daiki, etc.) may vary

1. Single kanji with a set meaning in isolation → kunyomi
   木 (ki, tree), 日 (hi, sun/day), 月 (tsuki, moon/month)

These are guidelines, not rules — exceptions are common, and many kanji have both onyomi and kunyomi forms used in different contexts.

Multiple Readings per Kanji

Many kanji have more than one onyomi (due to different waves of Chinese borrowing) and sometimes multiple kunyomi as well.

Example — 生 (live/raw/birth):

The character 生 has more than 10 distinct readings — it is one of the most complex kanji in common use.

Common Misconceptions

“Each kanji has exactly one onyomi and one kunyomi.”

Many kanji have multiple readings in each category. 生 (life/birth) has several onyomi (セイ, ショウ) and kunyomi (い.きる, う.まれる, なま, は.える), and the correct reading depends entirely on the word context. Learners who try to memorize “the” reading for each kanji are working against how the language actually operates.

“Onyomi is for formal/written Japanese and kunyomi is for spoken Japanese.”

Both reading types appear throughout spoken and written Japanese. Kunyomi-based words like 食べる (taberu, to eat) are perfectly standard in formal writing, and onyomi-based compounds like 電話 (denwa, telephone) are used constantly in casual speech. The distinction is etymological (Chinese-borrowed vs. native Japanese), not register-based.

“You should memorize all readings of a kanji before learning words that use it.”

This inverts the effective learning order. Readings are best acquired through vocabulary — learning the word 山 (やま, mountain) and 登山 (とざん, mountain climbing) naturally teaches both the kunyomi and onyomi of 山. Drilling abstract reading lists produces knowledge that is difficult to retrieve in context. Most effective SRS approaches prioritize vocabulary forms that embed the correct reading.

“Compound words always use onyomi.”

While two-kanji compounds (jukugo) most often use onyomi, there are many exceptions: 場所 (ばしょ, place) uses onyomi for both, but 手紙 (てがみ, letter) uses kunyomi for both. Mixed-reading compounds (重箱読み and 湯桶読み) combine onyomi and kunyomi within a single word. The “compounds = onyomi” rule is a useful starting heuristic, not a reliable rule.

Practical Application

For learners using tools like Anki or WaniKani:

• WaniKani teaches one reading per kanji (usually the most common reading in compounds) first, then introduces vocabulary to cover other readings in context.
• Anki sentence mining exposes learners to readings in context, which research suggests is more effective than isolated reading memorization.
• JLPT study decks often tag each vocabulary item with its reading type.

A common mistake is trying to memorize all readings of a kanji abstractly before encountering the words that use them. Most effective SRS strategies prioritize learning vocabulary forms that naturally encode the reading, rather than drilling readings in isolation.

Related Terms

• Kanji — the writing system these readings belong to
• Furigana — the reading guide often placed above kanji
• Joyo Kanji — the standard list of kanji for general use
• WaniKani — a structured SRS tool for learning kanji readings
• JLPT — the proficiency test where kanji reading knowledge is assessed

Research

• Unger, J. M. (1996). Literacy and Script Reform in Occupation Japan. Oxford University Press.
• Gottlieb, N. (2005). Language and Society in Japan. Cambridge University Press.
• Frellesvig, B. (2010). A History of the Japanese Language. Cambridge University Press.

See Also

• Sakubo