Onyomi vs Kunyomi: How Kanji Readings Work

Most kanji have two kinds of reading. The onyomi (音読み, sound reading) comes from the way the character was pronounced in Chinese when it was borrowed into Japanese. The kunyomi (訓読み, meaning reading) is a native Japanese word that was matched to the character because it had the same meaning.

Take 山, mountain. Japanese already had the word やま for mountain, so that became the kunyomi. The Chinese pronunciation was adapted as さん, which became the onyomi. That is why 山 alone is やま, but Mount Fuji is 富士山 (ふじさん).

What is onyomi?

Onyomi readings are usually short, often one or two syllables. They show up mostly in compound words made of two or more kanji, which are common in formal, technical and written Japanese. For example, 学 (がく) and 生 (せい) combine into 学生 (がくせい, student).

Because Japanese has fewer sounds than Chinese, many kanji ended up sharing the same onyomi. 校 (school), 高 (high), 行 (go) and 口 (mouth) can all be read こう. Some kanji also have several onyomi, because characters were borrowed at different times and from different regions of China. 人 has じん as in 日本人 (にほんじん, Japanese person) and にん as in 三人 (さんにん, three people). In dictionaries, onyomi are traditionally written in katakana to set them apart.

What is kunyomi?

Kunyomi readings are native Japanese words, so they tend to be longer and are often used when a kanji stands alone. When a kanji writes a verb or adjective, the kunyomi usually comes with hiragana endings called okurigana. In 食べる (たべる, to eat), the kanji 食 is read た and べる is okurigana. In 新しい (あたらしい, new), the kanji 新 is read あたら and しい is okurigana.

Dictionaries traditionally write kunyomi in hiragana, often with a dot or parentheses marking where the okurigana begins, for example た(べる).

Not every kanji has both kinds. 駅 (えき, station) and 電 (でん, electricity) are used with their onyomi only in everyday Japanese. On the other side, some kanji created in Japan, such as 畑 (はたけ, field), usually have only a kunyomi.

Examples side by side

Rules of thumb for guessing the reading

• Kanji on its own: usually kunyomi. 水 by itself is みず.
• Kanji followed by hiragana endings: almost always kunyomi. 見る is みる.
• Two or more kanji together: usually onyomi. 大学 is だいがく.
• Some compounds use kunyomi throughout, especially everyday words: 手紙 (てがみ, letter) and 大雨 (おおあめ, heavy rain).
• Some compounds mix the two. 毎朝 (まいあさ, every morning) pairs the onyomi まい with the kunyomi あさ.
• Some words have special readings that do not split neatly into either type, such as 今日 (きょう, today), 明日 (あした, tomorrow), 大人 (おとな, adult) and 一人 (ひとり, one person). These are called jukujikun, explained in jukujikun and ateji.

These patterns are right often enough to be worth knowing, but they are guides rather than laws. When in doubt, look up the word, not the single kanji. A dictionary entry for a single character lists every reading it can take, while the entry for a word tells you the one reading that word actually uses.

Here is how the rules play out in one sentence: 毎日、日本語を話します (まいにち、にほんごをはなします, I speak Japanese every day). 毎日 and 日本語 are compounds, so they use onyomi. 話します has hiragana endings, so 話 takes its kunyomi はな. The same kanji 日 appears twice with two different readings, にち and に, and the surrounding word tells you which.

Sound changes to expect

Readings often shift slightly when kanji join together. Sometimes a sound doubles: 学 (がく) and 校 (こう) combine into 学校 (がっこう, school), not がくこう. Sometimes the first sound of the second part becomes voiced, a change called rendaku: かみ (paper) becomes がみ in 手紙 (てがみ). Counters change too, as in 一本 (いっぽん), 三本 (さんぼん) and 六本 (ろっぽん). You do not need to memorize rules for this. You will absorb the patterns as you learn words.

The useful flip side is that once you know a few onyomi, you can often guess new compounds. If you know 電 (でん) and 車 (しゃ), you can read 電車 (でんしゃ, train) on first sight. If you know 新 (しん) and 聞 (ぶん), 新聞 (しんぶん, newspaper) follows. This is one of the biggest payoffs of learning kanji properly.

How to study readings without getting overwhelmed

1. Learn readings through words. For each kanji, learn one or two common words and their readings, instead of the full list of readings in a dictionary entry.
2. Start with the readings you actually meet. Some listed readings are rare. Common words will show you which ones matter.
3. Notice onyomi families. Kanji that share a component often share an onyomi, which our kanji radicals guide explains.
4. Review with spaced repetition so readings stick. See spaced repetition for Japanese, and our guide on how to learn kanji for the full routine.

If you can read a word but cannot say whether a reading is onyomi or kunyomi, that is fine. The labels are a tool for understanding patterns, not something you need to recall while reading.

Moji teaches each kanji with its readings and example words, then brings them back in spaced repetition reviews and Lock Screen widgets, from JLPT N5 up to N1.