On'yomi vs Kun'yomi: Kanji Readings Explained
✍️ Mori-sensei · Japanese Teacher · Updated 2026-06-22
Most kanji have at least two kinds of reading: 音読み (on, borrowed from Chinese) and 訓読み (kun, native Japanese). Knowing which is which — and when each one is used — is the key to reading kanji confidently. Here is how they work.
What are 音読み and 訓読み?
音読み (on-reading) comes from the Chinese pronunciation of the character at the time it was borrowed into Japanese. It is mostly used in 熟語 — compound words written with two or more kanji. For example, 山 in 富士山 (ふじさん) is read さん, an on-reading.
訓読み (kun-reading) is the native Japanese word that was matched to the character for its meaning. It is used when a kanji stands alone or is followed by hiragana endings called okurigana. For example, 山 on its own is read やま, a kun-reading.
A rule of thumb (with caveats)
- •A compound of two or more kanji with no hiragana between them is usually read with on-readings: 火山 (かざん, volcano), 学生 (がくせい, student).
- •A single kanji on its own, or a kanji followed by hiragana okurigana, is usually read with a kun-reading: 火 (ひ, fire), 食べる (たべる, to eat).
These are tendencies, not laws. Plenty of common words break them — 毎日 (まいにち) mixes patterns, and many place names and surnames follow their own logic. There are also 重箱読み and 湯桶読み, words that mix an on-reading and a kun-reading. So use the rule of thumb to make a smart first guess, then learn each word as it really is.
Worked examples
The clearest way to feel the difference is to see the same kanji in both roles.
- •山: alone it is やま (kun) — the word for mountain. In 富士山 (ふじさん) it is さん (on), inside a compound name.
- •火: alone it is ひ (kun) — fire. In 火曜日 (かようび, Tuesday) it is か (on), inside a compound.
- •食: with an okurigana ending, 食べる is たべる (kun, to eat). In the compound 食堂 (しょくどう, cafeteria) it is しょく (on).
Notice the pattern: alone or with hiragana, it leans kun; locked inside a multi-kanji word, it leans on. That single observation will get you a long way.
Frequently asked questions
Do I have to memorize every reading of a kanji?
No. Learn readings inside real words rather than as bare lists. The common readings will stick naturally because you meet them again and again in vocabulary, and rarer readings can wait until you actually encounter them.
How do I know which reading to use when I see a new word?
Use the rule of thumb — multi-kanji compound leans on-reading, a single kanji or kanji-plus-hiragana leans kun-reading — to make a first guess, then confirm with a dictionary or your course. Over time the patterns become intuition.
Are on and kun readings ever mixed in one word?
Yes. Words that mix an on-reading and a kun-reading are called 重箱読み or 湯桶読み. They are not the majority, but they are common enough that you should learn each word as it is rather than assuming.