Open any kanji dictionary and you will see two lists of readings under each character: one in katakana and one in hiragana. The first are the on'yomi (音読み), the second are the kun'yomi (訓読み). This is the point where many learners stop enjoying kanji, because a character like 生 can be read as セイ, ショウ, い(きる), う(む), は(える), なま, and more.
You do not need to memorize every reading of every character. You need a way to choose the right one. Here is how.
Where the two readings come from
- On'yomi are readings borrowed from Chinese when kanji arrived in Japan. They approximate the original Chinese sounds, adapted to Japanese. Written in katakana in dictionaries.
- Kun'yomi are native Japanese words that were matched to the meaning of the kanji. Written in hiragana in dictionaries.
So 山 has the on'yomi サン (as in 富士山, ふじさん) and the kun'yomi やま (as in 山, やま, the mountain).
Rule of thumb 1: Compounds usually use on'yomi
When two or more kanji sit together, the reading is usually on'yomi.
- 学校 (がっこう)
- 電話 (でんわ)
- 先生 (せんせい)
- 新聞 (しんぶん)
If you meet an unknown compound, start by guessing on'yomi readings.
Rule of thumb 2: A kanji with okurigana usually uses kun'yomi
Okurigana are the hiragana attached to a kanji. They signal a native Japanese word, so the reading is kun'yomi.
- 食べる (た-べる)
- 高い (たか-い)
- 話す (はな-す)
- 大きい (おお-きい)
Rule of thumb 3: A single kanji with no okurigana is often kun'yomi
- 山 (やま)
- 川 (かわ)
- 花 (はな)
- 人 (ひと)
But there are exceptions: single kanji read with on'yomi include 本 (ほん), 肉 (にく), 駅 (えき), and 茶 (ちゃ). Learn these as words rather than rules.
Rule of thumb 4: Mixed readings exist
Some compounds mix on'yomi and kun'yomi. They are called jūbako (重箱) readings when the first kanji is on'yomi and the second is kun'yomi, and yutō (湯桶) readings when it is the other way around.
- 重箱 (じゅう・ばこ): on + kun
- 湯桶 (ゆ・トウ): kun + on
- 場所 (ば・しょ): kun + on
- 本棚 (ほん・だな): on + kun
Do not worry about the category names. The practical lesson is simply: do not assume a compound is purely one type.
Rule of thumb 5: Sound changes happen
Readings often change at the boundary of a compound.
- 学 (がく) + 校 (こう) → がっこう (small っ)
- 日本 can be read にほん or にっぽん
- 三 + 本 → さんぼん (the ほ voices to ぼ)
Counters show these shifts most clearly; see Japanese counters for beginners for the sound changes that apply to 本, 匹, and others.
How to learn readings efficiently
1. Learn words, not isolated readings
Instead of memorizing "生 = セイ, ショウ, い, う, は, なま", learn:
- 先生 (せんせい)
- 学生 (がくせい)
- 生きる (いきる)
- 生まれる (うまれる)
- 生ビール (なまビール)
When a reading is attached to a real word, you remember both together.
2. Start with the most common reading
For beginners, focus on the reading you meet most in the level you are studying. N5 kanji usually have one or two readings you need. Check an N5 list in the JLPT N5 kanji count and how to learn them.
3. Use radicals and phonetic components
Many kanji share on'yomi because they share a phonetic part. 校, 交, 効, and 郊 are all read こう. See learning kanji with radicals for how to use that to your advantage.
4. Review readings in spaced repetition
A deck that shows the word and asks for the reading is the right test. The method is explained in spaced repetition for JLPT vocabulary and kanji.
What the JLPT asks
Reading questions on the vocabulary section give you a word in kanji and ask which hiragana reading is correct. The wrong options usually use plausible but wrong readings: the kun'yomi where the on'yomi belongs, or a missing small っ or long vowel. This is why learning words with their readings beats learning kanji alone.
A mistake log helps here: write down every reading you got wrong, with the word and the correct reading, and review it weekly.
Next steps
For a map of how kanji fits into your overall plan, see the JLPT preparation guide. JLPT Ready organizes kanji by chapter with plain-language explanations and links to the practice questions that test each one. You can start free with N5, no card required.