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Same Reading, Different Kanji: く vs く and 11 More Sets

One spoken word, several written forms, and each one makes a narrower claim than the last. This is where kanji stops being decoration and starts carrying meaning.

Published August 1, 2026 · 15 min read

Japanese frequently writes one spoken word with several different kanji, each narrowing the meaning. く is hearing in general, く is listening on purpose. う is meeting a person, う is fitting together, う is running into something unpleasant. The technical name is 異字同訓いじどうくん. The rule that saves you: the more specific kanji makes a claim, so if you are not sure the claim is true, use the general kanji or write the word in kana.

There is a specific moment, usually somewhere around N3, when a dictionary stops helping you and starts making things worse. You look up "to measure" and it hands you five kanji. You look up "to see" and it hands you four. Nothing marks which one is normal, nothing explains when the others apply, and the example sentences all look equally plausible.

This is not the dictionary being unhelpful. It is Japanese telling you something you have not been told yet: the kanji is not a spelling of the word. It is a claim about which sense of the word you mean. Once that lands, this whole area stops being a memorisation nightmare and becomes one of the most satisfying parts of the language.

Why one word ends up with five kanji

The Japanese words came first. When Chinese characters arrived in Japan, there was already a spoken language with a word はかる meaning roughly "to work out how much of something there is." Chinese had no single character for that. It had そく for physical dimensions, けい for counting, りょう for quantity, for plans, for consultation. Scribes matched the one Japanese word onto all of them. The spoken word never split, so today it has one sound and five spellings.

That history has a practical consequence worth stating plainly. When a Japanese writer chooses る over る, they are adding information that the spoken sentence does not carry. A reader who only knows る does not merely miss a character. They miss the fact that a doctor is involved. This is why the distinctions matter far more for reading than for writing.

The 12 sets that actually come up

Each set below gives the rule, a sentence with furigana and a full translation, and a safe default for when you genuinely cannot decide.

あうto meet, to match, to encounter3 kanji
a person

Meeting a person. This is the everyday one.

明日あしたえき友達ともだちいます。あしたえきでともだちにあいます。I am meeting a friend at the station tomorrow.

fits

Two things matching or fitting: sizes, tastes, opinions, answers.

このくつはサイズがいません。このくつはサイズがあいません。These shoes are not the right size.

bad luck

Running into something unwelcome: an accident, a storm, a crime. Never used for people you are pleased to see.

かえみち事故じこいました。かえりみちでじこにあいました。I was in an accident on the way home.

Default: if a human being is involved, it is う. The particle also helps: 〜に会う for people, 〜が合う for things matching.
きくto hear, to listen, to ask3 kanji
general

Sound reaching you, and also asking someone something. Covers most situations.

みちいてもいいですか。みちをきいてもいいですか。May I ask you for directions?

on purpose

Listening attentively and deliberately. Standard for music, concerts, and careful listening in interviews or counselling.

毎朝まいあさ電車でんしゃ音楽おんがくいています。まいあさでんしゃでおんがくをきいています。I listen to music on the train every morning.

rare

Specifically asking a question. Outside the jōyō list, so newspapers and textbooks write く instead. Worth recognising in novels.

理由りゆういてみた。りゆうをきいてみた。I tried asking why.

Default: く is never wrong. Reach for く only when the listening was chosen rather than incidental.
みるto see, watch, examine, care for4 kanji
general

Seeing, looking, glancing. The default for almost everything.

まどからうみえます。まどからうみがみえます。You can see the sea from the window.

a show

Watching something staged to be watched: a film, a play, a match. Sitting down for it is the point.

週末しゅうまつ映画えいがきます。しゅうまつにえいがをみにいきます。I am going to see a film at the weekend.

medical

A doctor examining a patient. One character tells you the whole context.

先生せんせいてもらったほうがいいですよ。せんせいにみてもらったほうがいいですよ。You had better get a doctor to look at that.

caring

Looking after someone who is ill. Same character as 看護かんご, nursing.

ははながらはたらいています。ははをみながらはたらいています。I am working while caring for my mother.

Default: る. Note that る is a stylistic choice many writers skip, but る and る genuinely change the meaning and cannot be swapped.
はかるto measure, to plan, to consult5 kanji
length

Dimensions: length, distance, depth, speed. The water radical 氵 hints at depth and flow.

部屋へやひろさをはかってください。へやのひろさをはかってください。Please measure the size of the room.

time

Time and counting. Contains 言, the calculating radical, and lives in 時計とけい and 計算けいさん.

ストップウォッチで時間じかんはかります。ストップウォッチでじかんをはかります。I time it with a stopwatch.

weight

Weight and volume. Same character as 重量じゅうりょう, weight.

毎朝まいあさ体重たいじゅうはかっています。まいあさたいじゅうをはかっています。I weigh myself every morning.

plan

Not measuring at all. Planning or attempting something, as in a diagram or scheme.

問題もんだい解決かいけつはかる。もんだいのかいけつをはかる。To work toward solving the problem.

consult

Formally consulting a body: a committee, a council, a board. Almost exclusively written and official.

このけん委員会いいんかいはかります。このけんはいいんかいにはかります。This matter will be referred to the committee.

Default: for physical measurement, はかる is the safest of the three. はかる and はかる are different verbs wearing the same sound and cannot substitute for the others.
なおすto fix, to cure2 kanji
objects

Repairing an object, or correcting a mistake. Also "do it again" as a suffix: なおす.

自転車じてんしゃなおしてもらいました。じてんしゃをなおしてもらいました。I had my bicycle repaired.

illness

Curing an illness or injury. Same character as 治療ちりょう, treatment.

風邪かぜはやなおしたいです。かぜをはやくなおしたいです。I want to get over this cold quickly.

Default: the line is clean. Bodies take なおす, everything else takes なおす. The same split runs through the intransitive なおる and なおる.
つくるto make, to build, to create3 kanji
everyday

Making something small or everyday: food, documents, plans, songs.

今夜こんやはカレーをつくります。こんやはカレーをつくります。I am making curry tonight.

large scale

Building something large or industrial: ships, buildings, bridges, and by tradition sake and miso.

このまちではむかしからさけつくっています。このまちではむかしからさけをつくっています。This town has brewed sake since long ago.

original

Creating something that did not exist before. Same character as 創造そうぞう and 創立そうりつ.

あたらしい文化ぶんかつくる。あたらしいぶんかをつくる。To create a new culture.

Default: つくる covers the overwhelming majority of cases. The other two are deliberate choices that carry scale or originality.
かたいhard, firm, dependable3 kanji
vs soft

Physically hard rather than soft. The stone radical 石 gives it away. Also used of stiff, inflexible writing.

このパンはかたすぎます。このパンはかたすぎます。This bread is too hard.

vs loose

Firm, solid, tightly fixed rather than loose. Also used of resolve and of promises.

かれ決意けついかたかった。かれのけついはかたかった。His resolve was firm.

dependable

Sturdy and reliable, used of people, jobs and businesses. かたひと is a serious, dependable person.

彼女かのじょかた仕事しごとについている。かのじょはかたいしごとについている。She has a steady, respectable job.

Default: ask what the opposite is. Opposite of soft, use かたい. Opposite of loose, use かたい. Opposite of frivolous, use かたい. Kana is very common here and completely acceptable.
あついhot, thick3 kanji
weather

Hot weather or air. Contains 日, the sun.

今年ことしなつ本当ほんとうあついですね。ことしのなつはほんとうにあついですね。This summer really is hot, isn't it.

objects

A hot object or liquid, and by extension passionate feeling. Contains 灬, fire.

あついおちゃをいただけますか。あついおちゃをいただけますか。Could I have a hot cup of tea?

thick

Not hot at all. Thick, of books, coats and slices, and figuratively of hospitality.

あつほん一冊いっさついました。あついほんをいっさつかいました。I bought one thick book.

Default: weather versus object splits あつい and あつい cleanly. あつい is a different word entirely and context makes it obvious.
とるto take, photograph, collect, catch4 kanji
general

Taking, picking up, obtaining. The broad default.

そこのしおってください。そこのしおをとってください。Please pass me the salt.

camera

Taking a photograph or filming. Unavoidable in daily life.

写真しゃしんってもいいですか。しゃしんをとってもいいですか。Is it all right if I take a photo?

select

Adopting, collecting or hiring: a policy, a blood sample, a new employee. Same character as 採用さいよう.

って検査けんさします。ちをとってけんさします。We will take a blood sample and run tests.

capture

Catching something that could get away: fish, insects, a suspect.

かわさかなりました。かわでさかなをとりました。I caught fish in the river.

Default: る for anything ordinary. る is the one to learn actively, because you will need it constantly and る genuinely looks wrong there.
かえるto change, exchange, replace4 kanji
nature

Changing what something is like: a plan, a colour, an attitude. The thing stays, its nature changes.

予定よていえてもいいですか。よていをかえてもいいですか。Would it be all right to change the plan?

exchange

Exchanging one thing for another, often across a boundary: money, batteries, air. Same as 交換こうかん.

えんをドルにえたいのですが。えんをドルにかえたいのですが。I would like to change yen into dollars.

substitute

Swapping in another of the same kind. Lives inside 着替きがえる and 両替りょうがえ.

ふく着替きがえてからかけます。ふくをきがえてからでかけます。I will change clothes and then go out.

stand in

Having something stand in for something else, often a role or a person.

メールをもって挨拶あいさつえさせていただきます。メールをもってあいさつにかえさせていただきます。Please allow this email to stand in for a proper greeting.

Default: える if the thing itself becomes different, える or える if one item leaves and another arrives. This set is the most commonly written in kana of all twelve.
おさめるto obtain, master, govern, pay4 kanji
obtain

Taking in or storing away, and idiomatically achieving a result.

おおきな成功せいこうおさめました。おおきなせいこうをおさめました。They achieved a great success.

master

Mastering a discipline through study. Same as 修士しゅうし, a master's degree.

大学だいがく法律ほうりつおさめた。だいがくでほうりつをおさめた。He studied law at university.

govern

Governing or bringing under control. The same character as curing an illness, and the logic is the same: restoring order.

くにおさめるのは簡単かんたんではない。くにをおさめるのはかんたんではない。Governing a country is not simple.

pay

Paying or delivering what is owed. Same as 納税のうぜい, paying tax.

期限きげんまでに税金ぜいきんおさめてください。きげんまでにぜいきんをおさめてください。Please pay your taxes by the deadline.

Default: this set is almost entirely written vocabulary, so learn it as four separate compounds rather than one verb with four faces.
のぼるto go up, climb, rise3 kanji
general

Going up in general, including figuratively.

階段かいだんのぼって二階にかいきます。かいだんをのぼってにかいへいきます。Go up the stairs to the second floor.

with effort

Climbing something that takes effort: a mountain, a tree, a ladder.

去年きょねん富士山ふじさんのぼりました。きょねんふじさんにのぼりました。I climbed Mount Fuji last year.

rise

Rising smoothly without effort: the sun, smoke, a promotion. Contains 日.

朝日あさひうみからのぼってきた。あさひがうみからのぼってきた。The morning sun rose out of the sea.

Default: effort decides it. Your legs are working, use のぼる. Nothing is working, use のぼる. Unsure, use のぼる.

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Four principles that cover the sets you have not met yet

1. The specific kanji makes a claim

Writing う says the encounter was unwelcome. Writing る says a medical professional is looking. If you are not certain the claim is true, the general kanji is not a compromise, it is the correct answer.

2. Learn the kanji's field, not the pairing

Do not memorise "はかる has five kanji." Learn that そく belongs to physical dimensions, りょう to quantity, to formal consultation. The choice then falls out of what you already know, and it generalises to compounds you have never seen.

3. The compound is the giveaway

Almost every one of these characters appears in a common two kanji word that spells out its meaning: 採用さいよう for 採, 交換こうかん for 換, 治療ちりょう for 治, 看護かんご for 看. If you can recall the compound, you can derive the verb.

4. Kana is a legitimate answer

Native writers use kana constantly for exactly this reason, and official style guides mandate it for readings outside the jōyō list. Kana is neutral. A wrong kanji is not.

The mistake to avoid: reaching for the rarest kanji because it looks more advanced. Writing く in a business email or る anywhere does not read as sophisticated, it reads as someone who learned from a dictionary rather than from reading. Native writing is more conservative than learners expect.

Why this matters more for reading than for writing

Here is the reframe that makes the whole topic feel worth the effort. You will rarely be forced to choose one of these kanji yourself, because you can write kana, and because input software offers the options with descriptions attached. What you cannot avoid is reading them.

Compare two sentences that sound completely identical when spoken:

ははています。ははをみています。I am looking at my mother.

ははています。ははをみています。I am caring for my mother.

Same sound, same kana, entirely different life. In speech, context and intonation resolve it. In writing, the kanji is doing the work by itself, and a reader who treats 看 as an unfamiliar variant of 見 has just misunderstood the sentence without noticing. This is exactly the kind of loss the JLPT reading section is built to detect, and it is why these distinctions climb steadily in weight from N3 through N1.

How to actually learn them

Flat lists fail here, and they fail for a specific reason: the twelve sets above contain around forty characters whose only shared feature is a sound. There is nothing for memory to grip. What works is meeting each character inside a sentence where the choice is doing visible work, and meeting it again before it fades.

That is the shape of Kanjijo. Every kanji and every vocabulary item carries an exclusive mnemonic written to be remembered rather than translated, and every example sentence carries furigana over the kanji and a full English translation underneath, so you see why that character was chosen rather than being told to memorise a pairing. The SRS engine then schedules each item for the day you are about to lose it, which matters more here than almost anywhere else, because near-identical items decay by blurring into each other rather than by disappearing.

Between sessions the material keeps working. The home screen and lock screen widgets put today's items where your eyes already go, and the test widget quizzes you straight from the home screen. When you hit one of these characters in the wild, on a hospital sign, a menu or a form, the OCR scanner reads it off the image and turns it into a study item on the spot.

And because reading is where these distinctions actually bite, the JLPT reading track puts them back in front of you inside full passages, with listening sets, full mock exams, and conversation, shadowing and dictation covering the half of the language a kanji chart cannot reach.

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Quick reference

あう
会う person · 合う fits · 遭う something bad
きく
聞く general · 聴く on purpose · 訊く ask (rare)
みる
見る general · 観る a show · 診る medical · 看る caring
はかる
測る length · 計る time · 量る weight · 図る plan · 諮る consult
なおす
直す objects · 治す illness
つくる
作る everyday · 造る large scale · 創る original
かたい
硬い vs soft · 固い vs loose · 堅い dependable
あつい
暑い weather · 熱い objects · 厚い thick
とる
取る general · 撮る photos · 採る select · 捕る catch
かえる
変える nature · 換える exchange · 替える substitute · 代える stand in
おさめる
収める obtain · 修める master · 治める govern · 納める pay
のぼる
上る general · 登る with effort · 昇る rise

Learn the character's meaning, not the pairing

Kanjijo gives you the full kanji, vocabulary and grammar bank for every JLPT level, exclusive mnemonics on every item, furigana and English on every example sentence, an SRS engine, lock screen and home screen widgets, a test widget, OCR scanning, JLPT reading and listening practice, mock exams, conversation, shadowing and dictation.

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Frequently Asked Questions

Because the Japanese words existed before the characters did. When Chinese writing arrived, a single Japanese word such as はかる was mapped onto several different Chinese characters, each covering a narrower slice of its meaning. The spoken word never split, so one sound now has several written forms. The term for this is 異字同訓.

聞く is general: sound reaching you, and also asking someone something. 聴く is deliberate, attentive listening, which is why it is standard for music and concerts. 音楽を聴く is the normal choice; 音楽を聞く is not wrong but suggests the music simply happened to be audible.

測る for length, distance and depth; 計る for time and counting; 量る for weight and volume; 図る for planning or attempting; 諮る for formally consulting a committee. Each character carries its own field, so learning the field rather than the pairing makes the choice automatic.

No, and native writers do it constantly. Official style guides even require kana for readings outside the jōyō list, which is why 訊く usually appears as 聞く or きく. Kana is neutral, while the wrong kanji makes a specific claim that may be false.

Yes, from N3 upward and heavily at N2 and N1. The vocabulary section asks which kanji fits a context, and reading passages lean on the distinction to carry meaning, so a reader who flattens 看る into 見る loses information rather than just a character.

あう, きく, みる, なおす and とる, because all five appear constantly in everyday Japanese and each has a clean rule. Leave はかる, おさめる and かえる until N2 or later, since they are largely written vocabulary and are easier to absorb from reading than from a list.

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