On'yomi and kun'yomi: why kanji have two kinds of reading

Most kanji can be read in more than one way. This guide explains where the two kinds of reading come from, how to tell which one a word uses, the exceptions you will meet early, and how much to memorise at N5 and N4.

Where the two readings come from

Chinese characters reached Japan well over a thousand years ago. Japanese already had its own words, so the characters were put to two uses. They wrote the Chinese words that Japanese borrowed, pronounced roughly as Japanese speakers heard them. They also wrote native Japanese words with a similar meaning.

The first use gives the on'yomi (音読み, おんよみ), the "sound reading". The second gives the kun'yomi (訓読み, くんよみ), the "meaning reading". Take 山, mountain: its on'yomi サン comes from Chinese, while its kun'yomi やま is the native word, which Japanese had before anyone wrote it with 山.

Kanji dictionaries usually write on'yomi in katakana and kun'yomi in hiragana, so you can tell them apart at a glance: 山 is サン and やま.

Some kanji have more than one on'yomi because they were borrowed more than once, from different periods and regions of China. 人 is ニン in 三人 (さんにん, three people) and ジン in 日本人 (にほんじん, a Japanese person). 生 is セイ in 先生 (せんせい, teacher) and ショウ in 一生 (いっしょう, a lifetime). Others have several kun'yomi because one kanji was used for several related native words: 上 is うえ (above), あ-がる (to rise) and のぼ-る (to climb).

The main pattern: compounds or kana endings

Two or more kanji together usually take on'yomi

Most kanji compounds (熟語, じゅくご) are words borrowed from Chinese or built on the Chinese model, so they use on'yomi: 学生 (がくせい, student), 電車 (でんしゃ, train), 時間 (じかん, time), 新聞 (しんぶん, newspaper).

A kanji alone or with kana endings usually takes kun'yomi

A kanji standing on its own is usually a native word: 水 (みず, water) and 手 (て, hand). So is a kanji followed by okurigana (送り仮名, おくりがな), the kana that carry the ending of a verb or adjective: 食べる (たべる, to eat), 飲む (のむ, to drink), 高い (たかい, high), 新しい (あたらしい, new).

Okurigana are the strongest clue you have: a kanji with a verb or adjective ending is almost always read with a kun'yomi. The exceptions are a few verbs built on an on'yomi, such as 信じる (しんじる, to believe). Okurigana also tell you which kun'yomi: 上がる is あがる, but 上る is のぼる.

A quick check from the sound

On'yomi have a recognisable shape: one or two kana beats, and when there is a second beat it is almost always い, う, き, く, ち, つ or ん, as in ガク, ショク, セイ and ニチ. (A small kana such as the ョ in ショ belongs to the beat before it.) So あたら in 新しい, three beats long, must be a kun'yomi. The check only works one way: short readings such as め (eye) and て (hand) are kun'yomi too.

The exceptions you will meet early

Compounds read with kun'yomi

Some compounds are native words written with two kanji, so both halves take kun'yomi: 名前 (なまえ, name), 手紙 (てがみ, letter), 花火 (はなび, fireworks). Notice the second halves: かみ becomes がみ and ひ becomes び. This voicing, called rendaku (連濁, れんだく), is common when two native words join.

Mixed compounds

A few compounds mix the two. 毎朝 (まいあさ, every morning) and 本屋 (ほんや, bookshop) start with an on'yomi and end with a kun'yomi. 場所 (ばしょ, place) and 夕食 (ゆうしょく, evening meal) do the opposite. Japanese has names for the two patterns, 重箱読み (じゅうばこよみ) and 湯桶読み (ゆとうよみ), but you only need to learn each word as you meet it.

Kanji read with on'yomi even alone

Some common kanji have no everyday kun'yomi, so they use their on'yomi even when they stand alone: 駅 (えき, station), 肉 (にく, meat), 茶 (ちゃ, tea, usually お茶), 気 (き, spirit or mood). 本 has a kun'yomi, もと (origin), but on its own it is usually ほん, book.

Readings that belong to the whole word

Some common words have a reading that belongs to the whole word, not to each kanji. These are called jukujikun (熟字訓, じゅくじくん); learn them as vocabulary:

日本 and other sound changes

日本 is not really an exception. Both kanji take on'yomi: 日 is ニチ and 本 is ホン. Where they join, the sound changes, giving にっぽん or the more everyday にほん. The same kind of change turns ガク and コウ into 学校 (がっこう, school).

A single word can use both kinds of reading for the same kanji: 日曜日 (にちようび, Sunday) has ニチ at the start and ひ, voiced to び, at the end.

How much to memorise at N5 and N4

Don't memorise reading lists. A full entry for 生 or 下 includes readings you won't need for years, and a reading you cannot attach to a word won't help you read. The JLPT's kanji questions at N5 and N4 ask you to read whole words in a sentence, or to choose the right kanji for a word written in hiragana.

A workable target:

• At N5, learn the reading each kanji has in its most common word, plus a second reading when another common word needs it. For 行, that is い-く in 行く (いく, to go) and コウ in 銀行 (ぎんこう, bank). 人 needs ひと, ジン and ニン, because 人, 日本人 and 三人 are all N5 words.
• At N4, add second on'yomi as new words bring them in, and the extra kun'yomi of verbs that come in pairs, such as 出る and 出す (でる, だす) or 入る and 入れる (はいる, いれる).
• At both levels, learn the word first and file the reading afterwards. Once you know 先生, 学生 and 生まれる (うまれる, to be born), you have learnt セイ and う-まれる for 生 without drilling either.

Kanji that share a component often share an on'yomi. 門 (gate) and 問 (question) are both モン, as in 問題 (もんだい, problem). 反 and 飯 are both ハン, as in 反対 (はんたい, opposite) and ご飯 (ごはん, meal). Treat this as a hint, not a rule: 時 (ジ) and 待 (タイ) share the same right-hand part and read differently.

For a schedule, see the six-week N5 kanji plan. Every kanji on the N5 and N4 lists has its own page with its readings and an example word.