# On'yomi and kun'yomi: a kanji's two readings

> Why a single kanji reads two ways, how to tell on'yomi (Chinese-derived) from kun'yomi (native Japanese), and the simple rule to guess which one applies.

- Page: https://www.darumoji.com/en/guide/onyomi-vs-kunyomi
- Content written by Darumoji: https://www.darumoji.com
- Published 2026-06-16

After the kana, here's the next wall: one kanji can read two completely unrelated ways. Why does 水 (みず) sometimes read すい? The answer comes down to two families of readings, and one rule that bails you out most of the time.

**山 (やま / さん)**: One native Japanese reading (やま), one of Chinese origin (さん).

## Where the two readings come from

When Japan imported Chinese writing, it imported two things at once: the character **and** its rough Chinese pronunciation. That borrowed pronunciation is the **on'yomi** (`音読み`, おんよみ, "sound reading"). But the Japanese already had their own words for "mountain", "water", "eat": so they also pinned each character onto the existing Japanese word. That native word is the **kun'yomi** (`訓読み`, くんよみ, "meaning reading").

- **音読み (おんよみ)**: The **Chinese-derived** reading. Often short and clipped (すい, さん, せい). Dominates when the kanji is glued to another kanji.
- **訓読み (くんよみ)**: The **native Japanese word** mapped onto the character. Often longer, frequently followed by hiragana. Dominates when the kanji stands alone.

## The rule that works (almost always)

Kanji **alone** or followed by hiragana (okurigana) → usually **kun'yomi**. Kanji **glued to another kanji** in a compound word (`熟語`, じゅくご) → usually **on'yomi**. It's not an iron law, but it gives you the right reading in the vast majority of cases.

> 水を飲む。
>
> みず を のむ。
>
> Drink water.

`水` on its own, followed by a verb: **kun'yomi** reading みず.

> 水曜日
>
> すいようび
>
> Wednesday (literally "water day").

The same `水`, glued to other kanji: **on'yomi** reading すい. Same character, opposite reading.

## Why some kanji have several on'yomi

Japan didn't borrow Chinese in one go, but in waves, across several centuries and from different regions. The result: a single kanji can carry several on'yomi readings depending on when it was borrowed. The three main ones are `呉音` (ごおん, the oldest), `漢音` (かんおん, Tang era, the majority today) and `唐音` (とうおん, later borrowings).

## The extreme case: 生

The all-time champion is `生` (せい / しょう / なま / き depending on context). It stacks several on'yomi readings (せい, しょう) and many kun'yomi: `なま` (raw, fresh), `き` (pure), `いきる` (to live), `うまれる` (to be born). Don't panic: you never learn readings in a vacuum, you meet them word by word, and context almost always settles it.

> **Remember** **On'yomi = Chinese-derived reading**, dominates in compounds (`熟語`, じゅくご). **Kun'yomi = native Japanese word**, dominates when the kanji stands alone or is followed by hiragana. When in doubt, check whether the kanji is glued to another kanji.

---

## How many kanji do you actually need?

- [Continue](https://www.darumoji.com/en/guide/how-many-kanji-do-you-need)
- [Explore kanji](https://www.darumoji.com/en/kanji)