Why Japanese Kanji Has Two Readings (ON & KUN Explained Simply)

Table of Contents

• Introduction: Why Kanji Has Two Readings
• 1. Why Kanji Has Two Voices (ON & KUN Origins)
• 2. The Simple Rule: Alone or Together?
• 3. Why This Pattern Exists
• 4. ON vs KUN Through the VENOM Formula
• 5. The Big Mistake Most Learners Make
• 6. Quick ON vs KUN Practice
• Quick Review Summary
• FAQ: Japanese ON & KUN Readings

Introduction: Why Kanji Has Two Readings

Have you ever seen a kanji that seems to change sound depending on the situation?

Take 山 for example — sometimes it’s yama, other times san.

It feels like the same kanji is pretending to be two different people. This confuses every learner, but thankfully the reason is simple.

In this lesson, you’ll learn exactly why kanji have two readings, when to use ONYOMI and KUNYOMI, and how to guess the reading even when it’s your first time seeing the word.

 1. Why Kanji Has Two Voices (ON & KUN Origins)

A long time ago, Japan had no writing system. People spoke Japanese every day, but there were no characters and no way to write it down.

Then writing arrived from China, and Japan started using Chinese characters — what we now call kanji.

When Japan borrowed these characters, something important happened:

• Japan kept its own native Japanese words for basic things like “mountain,” “river,” and “person”.
• Japan also borrowed the Chinese-style pronunciation that came with the characters.

That’s how many kanji ended up with two main readings:

• The older native Japanese word → KUN reading (kunyomi)
• The newer Chinese-style sound → ON reading (onyomi)

Let’s look at the kanji 山:

• Long before kanji, Japanese people said yama for “mountain”. That native reading is the KUN reading.
• Later, Japan imported the character 山 from China, where it was pronounced something like shan. In Japanese this became san, the ON reading.

So you can think of each kanji as an actor with two voices:

• KUN = Japanese voice
• ON = Chinese-style voice

Same character, two voices — and both are correct in the right situation.

 2. The Simple Rule: Alone or Together?

Now let’s turn this history into a practical rule you can use right away.

Main pattern:

• If the kanji is alone or has hiragana attached at the end → it usually uses the KUN reading.
• If you see two or more kanji together forming one word → they usually use their ON readings.

🔹 1. Single kanji → usually KUN

When you see one kanji by itself, it often uses the KUN reading:

• 花 → hana (flower)
• 山 → yama (mountain)
• 人 → hito (person)

These are old, natural Japanese words. People were already saying hana, yama, and hito long before kanji existed.

🔹 2. Kanji + hiragana → usually KUN

Look at verbs written with kanji at the front and hiragana at the end:

• 聞く → kiku (to listen)
• 食べる → taberu (to eat)
• 飲む → nomu (to drink)

This pattern — kanji first, hiragana after — is almost always a KUN reading.

🔹 3. Kanji + kanji → usually ON

When you see two kanji joined together, that’s when ON readings usually appear:

• 新聞 → shinbun (newspaper)
• 学生 → gakusei (student)
• 電話 → denwa (telephone)
• 火山 → kazan (volcano)

Each kanji here uses its ON reading: 新 (shin), 聞 (bun), 学 (gaku), 生 (sei), 電 (den), 話 (wa), 火 (ka), 山 (san).

So the simple pattern is:

• Kanji stands alone or has hiragana after it → usually KUN.
• Kanji + kanji in one word → usually ON.

This rule isn’t perfect, but it works in most daily situations and makes kanji much more predictable.

3. Why This Pattern Exists

Here’s an easy way to feel the difference.

Many KUN readings belong to old, natural words:

• “mountain,” “river,” “person,” “fire,” basic actions and adjectives.

People were already using these words before kanji arrived, so they kept the Japanese pronunciation and simply attached kanji to it.

Many ON readings belong to newer, more constructed words:

• “newspaper,” “telephone,” “society,” “education,” and other abstract or combined concepts.

These were created later using kanji that came from China, so they usually follow the Chinese-style ON reading.

Easy memory trick:

• Everyday nature and basic actions → often KUN.
• More abstract ideas and compound nouns → often ON.

It’s not a strict rule, but a very helpful shortcut to train your brain.

 4. ON vs KUN Through the VENOM Formula

In the VENOM Formula, language is viewed through two big structures:

• Verbal → actions and states.
• Nominal → things and ideas.

Kanji fits this pattern beautifully.

KUN lives closer to the verbal, natural side

You’ll see KUN mainly in verbs and adjectives written as kanji + hiragana:

• 食べる → taberu (“to eat”)
• 聞く → kiku (“to listen”)
• 待つ → matsu (“to wait”)
• 高い → takai (“tall, expensive”)

These are actions and states you experience directly in real life, so they usually use the KUN reading.

ON sits closer to the nominal, concept side

ON readings show up more in nouns, especially compound nouns built from two kanji:

• 食事 → shokuji (“meal”)
• 電車 → densha (“train”)
• 文化 → bunka (“culture”)

These are not actions you do. They’re concepts, labels, and categories.

So you can ask yourself a simple question whenever you see a new word:

“Is this word acting more like an action, or more like a concept?”

• If it feels like an action or state and has hiragana after the kanji → it’s very likely KUN.
• If it feels like a thing or idea and is made of kanji + kanji → it’s very likely ON.

 5. The Big Mistake Most Learners Make

The biggest mistake many learners make is trying to memorize every single ON and KUN reading for every kanji.

If you do that, you’ll burn out very fast.

Instead of chasing perfection, focus on noticing patterns:

• Look for hiragana after the kanji. If it’s there, it’s often a verb or adjective using a KUN reading.
• Look for kanji + kanji used as one noun. That’s very often an ON-reading compound.
• Notice when a kanji reappears in different compounds with the same ON reading. For example, 学 in 学生 (gakusei) and 学校 (gakkou).

Also, don’t panic if one kanji has more than one ON reading or more than one KUN reading. Japan borrowed kanji from China at different times and from different regions, so some characters arrived with more than one “accent.”

You don’t need to remember everything at once. You just need a clear system in your head — and that’s what you’re building now.

 6. Quick ON vs KUN Practice

Let’s practice using the structure rule. Decide whether each word is using an ON or KUN reading:

1. 山 → yama

• Single kanji, stands alone as a word → KUN reading.

2. 火山 → kazan

• Two kanji joined together, one noun (“volcano”) → ON + ON combination.

3. 聞く → kiku

• Kanji + hiragana, verb (“to listen”) → KUN reading.

4. 新聞 → shinbun

• Two kanji, one concept (“newspaper”) → ON reading compound.

5. 食べる → taberu

• Kanji + hiragana, verb (“to eat”) → KUN reading.

6. 食事 → shokuji

• Two kanji together, abstract noun (“meal”) → ON reading compound.

If you can guess correctly just by looking at the structure — single kanji, kanji + hiragana, or kanji + kanji — your brain is already starting to see the pattern. That’s exactly what we want.

 Quick Review Summary

Let’s wrap everything up as simply as possible.

Kanji has two main readings:

• KUN reading (kunyomi) – native Japanese reading.
• ON reading (onyomi) – Chinese-style reading.

✔ When KUN Usually Appears

• Single kanji words: 山 (yama – mountain), 花 (hana – flower), 人 (hito – person).
• Verbs/adjectives with kanji + hiragana: 食べる (taberu – to eat), 聞く (kiku – to listen), 高い (takai – tall/expensive).

✔ When ON Usually Appears

• Compound nouns made of kanji + kanji: 新聞 (shinbun – newspaper), 学生 (gakusei – student), 電話 (denwa – telephone), 食事 (shokuji – meal).

✔ Shortcut Rules

• Kanji alone → usually KUN.
• Kanji + hiragana → usually KUN.
• Kanji + kanji (one noun) → usually ON.

In VENOM terms:

• KUN is closer to the verbal, natural side of the language — things you do and feel.
• ON sits closer to the nominal, concept side — labels, ideas, and compound words.

Once that idea clicks, kanji stops feeling like random guessing and starts to feel logical, structured, and even fun.

 FAQ: Japanese ON & KUN Readings

1. Why does one kanji have multiple ON readings?
Because Japan adopted kanji from China at different periods and from different regions, some characters came with several “accents,” which became multiple ON readings.

2. Do all kanji have both ON and KUN readings?
No. Some kanji only have ON readings, some only have KUN readings, and some have both.

3. What’s the best way to know which reading to use?
Look at the structure:

• Kanji alone → usually KUN.
• Kanji + hiragana → usually KUN.
• Kanji + kanji as one noun → usually ON.

Context and vocabulary are more important than memorizing every reading.

4. Should I try to memorize every ON and KUN reading?
No. Focus on the readings that appear in real words you actually use. Pattern recognition is far more effective than brute-force memorization.

5. Why do some words break these rules?
Japanese developed over many centuries, mixing native Japanese, Chinese influences, and historical changes. Because of that, there will always be exceptions — but the patterns above still help with the majority of words.

Keep these shortcuts in mind, and every time you see a new kanji, ask yourself: single kanji, kanji + hiragana, or kanji + kanji? Your brain will slowly turn ON vs KUN from a mystery into an automatic habit.