The short version: Japan's official kana rules, 現代仮名遣い (Modern Kana Usage, 1986), spell words the way they sound, with five fixed exceptions. (1) The particles は, へ and を are read wa, e and o. (2) 言う is spelled いう but sounds like yuu. (3) ぢ and づ are used for a repeated sound (ちぢむ, つづく) or where a word starting with ち or つ joins another (鼻血, 三日月); otherwise the standard spelling is じ and ず. (4) About twenty words spell a long o as おお instead of おう: おおきい, とおい, こおり. (5) A long e in words like 先生 and 映画 is spelled えい.
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Hiragana is often described as phonetic: one character, one sound. That is mostly true, and it is why you can read any hiragana text aloud after a few weeks of study. Then three puzzles appear. 私は is read watashi wa, not watashi ha. Two pairs of characters, じ and ぢ, ず and づ, make the same sound. And おおきい and おとうさん both contain a long o, but one spells it おお and the other おう.
All three come from Japan's official spelling rules, 現代仮名遣い, set by a Cabinet notice on 1 July 1986: write words as they are pronounced today, but keep a short list of established spellings as special cases. Most of those special cases mark a place where the pronunciation changed over the centuries and the spelling kept a trace of the older form.
| You write | You hear | Example | Why |
|---|---|---|---|
| は, へ, を | wa, e, o | 私は | The particles kept their old spelling. |
| いう | yuu | 言う | The other forms (言います, 言わない) have a clear i. |
| ぢ, づ | ji, zu | 鼻血 | The original ち or つ is still visible. |
| おお | oo | 大きい | The old spelling had ほ or を after the o. |
| えい | ee | 先生 | Words like this are written えい whether said ee or ei. |
The particles は, へ and を
When は, へ and を work as particles, they are read wa, e and o. Inside an ordinary word, は and へ keep their usual reading: はな (flower) is hana, and へや (room) is heya. を has no other job in modern Japanese, so it is always read o.
私は学生です。わたしはがくせいです。watashi wa gakusee desuI am a student.
毎朝、駅へ歩いて行きます。まいあさ、えきへあるいていきます。maiasa, eki e aruite ikimasuI walk to the station every morning.
寝る前に本を読みます。ねるまえにほんをよみます。neru mae ni hon o yomimasuI read a book before going to bed.
Why the particles kept the old spelling. In older Japanese, syllables of the は row in the middle or at the end of a word gradually shifted to わ-row sounds and plain vowels. Japanese dictionaries call this ハ行転呼. The word for river, for example, was spelled かは and came to be said kawa. Spelling did not follow the sound: the old system went on writing かは. を followed a separate path: it was once pronounced wo, and that sound later merged with お. When modern spelling switched to writing words by their sound, かは became かわ, but the particles は, へ and を were left alone. The official preface explains every special case the same way, as respect for established writing habits, and the particle spellings had survived the sound changes for about a thousand years: the は-row shift reached everyday words around the end of the 10th century.
The particle inside fixed words
Some everyday words were built from a phrase that contained the particle, and they keep its spelling. The official list includes こんにちは (hello), こんばんは (good evening), では (well then), または and あるいは (or), とはいえ (even so) and 恐らくは (in all likelihood). こんにちは began as the opening of a longer sentence, 今日は… (As for today…), with the rest left off, so its last character is the topic particle. You will see こんにちわ in casual messages, but the standard spelling is こんにちは.
こんにちは。今日はいい天気ですね。こんにちは。きょうはいいてんきですね。konnichiwa. kyoo wa ii tenki desu neHello. Lovely weather today, isn't it?
黒または青のペンで書いてください。くろまたはあおのペンでかいてください。kuro mata wa ao no pen de kaite kudasaiPlease write in black or blue pen.
春とはいえ、まだ寒いですね。はるとはいえ、まださむいですね。haru to wa ie, mada samui desu neIt may be spring, but it's still cold.
The rules also cover the reverse case. The sentence-ending わ in きれいだわ (oh, how lovely) grew out of the particle は, but it is no longer felt as the particle, so it is written the way it sounds: わ.
いう: written with い, heard as yuu
The verb 言う (to say) is spelled いう, but in normal speech its dictionary form sounds like yuu. Japanese dictionaries say so directly: the Nihon Kokugo Daijiten notes that the word is written いう and pronounced ユウ. The spelling makes sense once you conjugate the verb. 言います, 言わない and 言った are all pronounced with a clear i, so いう keeps the whole verb on one spelling. Forms such as ゆわない and ゆった are heard in casual speech, but dictionaries treat them as non-standard.
これはどういう意味ですか。これはどういういみですか。kore wa doo yuu imi desu kaWhat does this mean?
田中さんという人から電話がありました。たなかさんというひとからでんわがありました。tanaka-san to yuu hito kara denwa ga arimashitaThere was a call from someone called Tanaka.
言いたいことがあれば、言ってください。いいたいことがあれば、いってください。iitai koto ga areba, itte kudasaiIf you have something to say, please say it.
じ or ぢ, ず or づ
In standard Japanese, じ and ぢ are pronounced exactly the same, and so are ず and づ. (A few dialects, mainly in Shikoku and Kyushu, still keep some of these sounds apart.) The question is therefore only how to spell, and the answer starts with a default: write じ and ず. ぢ and づ are reserved for two situations.
Situation 1: a repeated sound
When ち is followed by a voiced ち, or つ by a voiced つ, the second one is written ぢ or づ. The official examples include 縮む (to shrink), 縮れる (to become curly or wrinkled), 続く (to continue), 鼓 (a hand drum) and 綴る (to spell out, to write). The rules name two look-alikes that do not count: いちじく (fig) and 著しい (remarkable) are written with じ.
この雨は週末まで続くそうです。このあめはしゅうまつまでつづくそうです。Apparently this rain will last until the weekend.
セーターを洗ったら、縮んでしまった。セーターをあらったら、ちぢんでしまった。I washed my sweater and it shrank.
Situation 2: two words joined, and the second began with ち or つ
When two words join, the first consonant of the second word often becomes voiced. This is rendaku, the same change that makes 本 bon in 三本 (see the rendaku guide). If the second word started with ち or つ, the voiced form is written ぢ or づ, so the original word stays visible in the spelling.
今朝、急に鼻血が出ました。けさ、きゅうにはなぢがでました。I suddenly had a nosebleed this morning.
このケーキは母の手作りです。このケーキはははのてづくりです。My mother made this cake herself.
日本の友だちから小包が届きました。にほんのともだちからこづつみがとどきました。A parcel arrived from a friend in Japan.
The first surprise: 世界中 is せかいじゅう
中 is read ちゅう, so the rule above seems to predict せかいぢゅう. The official text puts 世界中 in a separate group: words that people today generally no longer feel as two parts. For this group, じ and ず are the main spelling, and ぢ and づ are also accepted. The group includes 稲妻 (lightning, although 妻 is visible inside it), 絆 (a bond), 杯 (a sake cup), うなずく (to nod), つまずく (to trip) and ずつ in 一人ずつ (one at a time).
その歌は世界中で知られています。そのうたはせかいじゅうでしられています。That song is known all over the world.
一人ずつ名前を呼びます。ひとりずつなまえをよびます。I'll call your names one at a time.
駅の階段でつまずいてしまった。えきのかいだんでつまずいてしまった。I tripped on the stairs at the station.
The second surprise: 地面 is じめん
If you know 地 as ち, you might expect ぢめん. But 地 has two on-readings, ち and じ, and 地面 (the ground) simply uses じ, as 地震 (earthquake) does. Nothing became voiced when the word was formed, so neither situation applies. The same goes for 図, which has the on-reading ず: 地図 (map), 図画 (drawing), 略図 (a rough map). The official text gives じめん, ぬのじ (布地, cloth), ずが and りゃくず as its examples. (For more on why one kanji has several readings, see on'yomi vs kun'yomi.)
地震のあと、地面にひびが入っていた。じしんのあと、じめんにひびがはいっていた。After the earthquake, there were cracks in the ground.
地図を見ながら歩きました。ちずをみながらあるきました。I walked while looking at a map.
To choose, ask three questions in order:
- Is it ち then ぢ, or つ then づ, inside one word? Write ぢ or づ: ちぢむ, つづく. (Exceptions: いちじく, いちじるしい.)
- Is it a compound where a word starting with ち or つ is still visible? 血, 月, 作る, 包む, 付く: write ぢ or づ, as in はなぢ, みかづき, てづくり.
- Anything else? Write じ or ず. That covers words no longer felt as two parts (せかいじゅう, いなずま) and kanji that are simply read じ or ず (じめん, ちず).
おお or おう for a long o
A long o is normally written by adding う: お父さん (father), 公園 (park), 学校 (school), ありがとう. The official rules list a small group that adds お instead. These are the ones you will meet first:
The rest of the list can wait until you meet the words, since several of them are intermediate or advanced vocabulary:
The official list adds four rarer words (おおせ, ほおずき, しおおせる and いとおしい). Words built on any of these keep the spelling: 大きな, 大雨 (heavy rain), 大阪 (Osaka), 多く, 遠く, 通り (street) and 十日 (the tenth day).
Why these words. In the old spelling, each of them had ほ or を after the o-row kana: 大きい was おほきい, 氷 was こほり, 滞る was とどこほる, and 十 was とを. Inside a word, ほ came to be pronounced o through the same sound shift that made the particle は sound like wa, and を also came to sound like o. Modern spelling writes what is pronounced today, so both became お. Ordinary long o words came from different old spellings (中央 was ちゅうあう, 砂糖 was さたう), and those are written おう.
| Sounds like | Spelled おお | Spelled おう |
|---|---|---|
| oo | 大きい big | 王様 king |
| koo | 氷 ice | 公園 park |
| too | 通る to pass | 東京 Tokyo |
| hoo | 頬 cheek | 方法 method |
Your ear will not settle the question. The official rules state that these words are written おお whether they are pronounced as a long o or as two separate o sounds, so listening cannot tell you which group a word belongs to. The reason is historical, and the practical approach is to learn this short list: every other long o is おう.
このバスは大きな公園の前を通ります。このバスはおおきなこうえんのまえをとおります。kono basu wa ookina kooen no mae o toorimasuThis bus goes past a big park.
遠くの大きな氷の上を、多くの狼が十ずつ通る。とおくのおおきなこおりのうえを、おおくのおおかみがとおずつとおる。Across the big ice far away, many wolves pass by, ten at a time.
It covers とおい, おおきい, こおり, おおい, おおかみ, とお and とおる. As a bonus, ずつ follows the じ and ず rule above.えい and ええ for a long e
Long e has a similar split. In words like 先生 (teacher), 映画 (film), 時計 (clock) and 丁寧 (polite), the spelling ends in い, but in everyday speech you usually hear a long e: sensee, eega. The official rules say to write い whether the word is pronounced as a long e or as a clear ei, so you will hear both.
The spelling with え is the rare one. The official rules use it in ええ (yes) and お姉さん (older sister), and you will also see it in interjections such as ねえ and へえ. Kanji on-readings with this sound (先生 せい, 時計 けい, 映画 えい) are spelled with い, and so are some native words, such as 背 (height) and かれい (flounder), so えい is the spelling you will meet far more often.
先生、質問があります。せんせい、しつもんがあります。sensee, shitsumon ga arimasuExcuse me (to a teacher), I have a question.
週末に映画を見ました。しゅうまつにえいがをみました。shuumatsu ni eega o mimashitaI saw a film at the weekend.
ええ、そうです。ええ、そうです。ee, soo desuYes, that's right.
Typing: the keys follow the spelling
Japanese keyboards on phones and computers type by spelling, not by sound. The romaji system they use, called wāpuro rōmaji, gives every kana its own key sequence, including the ones that sound alike. If you have not set up a keyboard yet, this guide covers every device.
| To get | Type | Typing the sound gives |
|---|---|---|
| は (particle) | ha | wa → わ |
| へ (particle) | he | e → え |
| を | wo | o → お |
| ぢ | di | ji → じ |
| づ | du | zu → ず (dzu does not work) |
| おおきい | ookii | oukii → おうきい |
| せんせい | sensei | sensee → せんせえ |
We ran these keys and some sound-based spellings through Google's online converter (Google Input Tools) in October 2026, to see which mistakes the keyboard forgives. Mixing up ぢ and じ, or づ and ず, was forgiven once we converted: hanaji still offered 鼻血, and tsuzuku offered 続く and つづく. Vowel spelling was not: oukii, kooen and eega did not offer 大きい, 公園 or 映画, sensee did not offer 先生, and konnichiwa gave こんにちわ as its first suggestion. Other keyboards, especially on computers, may offer こんにちは as a correction, but you cannot count on it. Type the spelling and the right word appears; type the sound and you may not find it at all.
Check yourself: which spelling is standard?
Use the rules above. For ぢ and づ, ask whether a ち or つ word is still visible.
鼻血鼻 (hana, nose) + 血 (chi, blood)
The second word, 血, is still visible, so the voiced form is ぢ: はなぢ.
世界中世界 (sekai) + 中 (chuu)
Both are accepted, but the rules give せかいじゅう as the main spelling, because 世界中 is no longer felt as two separate words.
地面the ground, the surface
地 has the on-reading じ, as in 地震. Nothing was voiced, so it is じめん.
続くto continue
つ followed by a voiced つ is a repeated sound, so つづく.
大きいbig
大きい is on the おお list (old spelling おほきい), so おおきい.
遠いfar
遠い is on the おお list, so とおい.
公園park
公園 is not on the list, so the long o takes う: こうえん. Compare 氷, which is on it.
＿＿＿、田中さん。Hello, Mr Tanaka. (The greeting is read konnichiwa.)
The last character is the topic particle from 今日は…, so the standard spelling is こんにちは, read konnichiwa.
Related Reading on Kanjijo
Frequently Asked Questions
When は is the topic particle, it is read wa. In older Japanese, は-row syllables in the middle or at the end of a word came to be pronounced like the わ row, so the word for river, once spelled かは, was said kawa. Modern spelling writes ordinary words by their sound (かわ), but kept the old spelling for the particles は, へ and を. In ordinary words, は is still read ha: はな (hana, flower).
In standard Japanese they sound the same. The difference is only in spelling: write じ and ず by default, and ぢ or づ only for a repeated sound (ちぢむ, つづく) or for a compound whose second word began with ち or つ (鼻血, 三日月). 世界中 and 地面 are written with じ.
Only in a fixed group of about twenty words whose old spelling had ほ or を after the o, such as おおきい, おおい, とおい, とおる, とお (ten), こおり, おおかみ and ほのお. Words built on them keep the spelling: 大雨, 通り, 十日. Every other long o is written おう: おとうさん, こうえん, ありがとう.
The standard spelling is こんにちは. The greeting began as the start of a longer sentence, 今日は… (As for today…), so its last character is the topic particle は, read wa. You will see こんにちわ in casual messages, but it is not the standard spelling. On a keyboard, type konnichiha.
Type du for づ and di for ぢ. Typing zu and ji gives ず and じ, and dzu does not work. For the particles, type ha for は, he for へ and wo for を.
- Agency for Cultural Affairs (文化庁), 「現代仮名遣い」前書き: the principle of writing words by present-day pronunciation, with special cases that respect established spelling; and 訓令・告示制定文: Cabinet Notice No. 1 of 1 July 1986.
- Agency for Cultural Affairs, 本文 第1（原則に基づくきまり）: long vowels, including おとうさん, ねえさん and ええ.
- Agency for Cultural Affairs, 本文 第2（表記の慣習による特例）: the particles は, へ and を, いう, the two uses of ぢ and づ, the じ/ず group (せかいじゅう, いなずま, じめん, ずが), the おお word list and the えい note. Every word list in this article is taken from this page.
- Agency for Cultural Affairs, historical kana tables （イ～ワ） and （ユー～ロー）: old spellings with ほ and を (大きい, 氷, 滞る, 十日) and the old spellings of おう words (中央, 砂糖).
- Kotobank, は行転呼音 (Nihon Kokugo Daijiten; Heibonsha Mypedia): は-row syllables inside words pronounced as わ-row sounds and vowels, a change that reached everyday words from around the end of the 10th century.
- Kotobank, 言う (Digital Daijisen; Nihon Kokugo Daijiten): written いう, pronounced ユウ; ゆわない and ゆった are not the standard forms.
- Kotobank, 今日は (こんにちは as a shortened sentence) and わ (sentence-final わ developed from the particle は).
- Wikipedia, Yotsugana: じ/ぢ and ず/づ merged in standard Japanese; some dialects in Shikoku and Kyushu still distinguish them.
- Wikipedia, Historical kana orthography and Wāpuro rōmaji: the particle spellings as a remnant of the old system, and typing by spelling (ha, he, wo, du).
- Wikipedia, Early Middle Japanese: the syllables o and wo had merged by the 11th century.
- Self Taught Japanese, Distinguishing between 〜う words and 〜お words in Japanese: the children's mnemonic for seven おお words.
Hear every spelling rule as you learn it
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