Usage of Kun'yomi, On'yomi

Hi, im relatively new to learning japanese, and even newer to learinging the Kanji

So far i have picked up on the fact, about there being multiple readings for the same symbol. but i cant understand what is the actualy difference in usage.

is the kun’yomi even used in “normal” conversations?

and if not, what is it used for then?




On’yomi and kun’yomi are ways to pronounce a kanji, and you use the different readings depending on the word the kanji appears in. Take for example these two words:

() meaning fire
火山(かざん) meaning volcano

The same kanji 火 appears in both words, but it is read in two different ways. The on’yomi か is used for the second word, whereas the kun’yomi ひ is used for the first word. Basically, the word a kanji appears in determines how a word is read.

Usually when a kanji appears on its own, or appears with hiragana attached it will use the kun’yomi reading, and when it appears in a multi-kanji compound it will use on’yomi, however there are a lot of exceptions to this, so you’ll have to learn which reading to use when you learn vocabulary.


A quick and simplified rule that’ll help you a lot:

  • On’yomi: imported chinese readings, used mostly in word composition.
  • Kun’yomi: japanese original readings, used mostly for verbs and everyday words.
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Until you learn more about the structure of Japanese, it may help to just think of the readings as “context” based. The simplified version of the rules above will often look like “In a compound word it’s pronounced like this, but in a word by itself it’s pronounced like that”. Or “this word is an exception, because it uses this reading instead of the one I usually see”. That will get you started learning japanese, then you can start worrying about which are On’ and Kun’yomi readings.

Especially on WaniKani, because they don’t always stick to teaching On’yomi first, so it can be hard to make assumptions about what’s what.

Hello Ecrofer, I’m a beginner and I was floating in a sea of confusion too. I found this recently and thought that it helped a lot: Japanese on-readings and kun-readings - making them work for you - YouTube (it’s longish but you don’t have to watch the whole thing !) One reading (the purple one in WK) is like a whole word (eg water) and the other (the pink one in WK) is like a part-word that means the same thing (eg aqua in aquarium).


I’m curious what led to the question being posed this way. I would almost expect people to ask the opposite, if on’yomi get used in conversation.


To add on a bit to BIsTheAnswer’s response, it might help to remember that while WK may be teaching stuff kanji-first, the way it really works is more word-first. Remember, kanji are only written representations of concepts. Japanese people aren’t thinking about on’yomi vs kun’yomi as they speak or write. They’re a little like root-words in English.

There’s a word for “water”. The word is pronounced みず. That word written in kanji is 水. So we end up saying the kun’yomi for 水 is みず.
There is also a word for “underwater”. It’s pronounced すいちゅう. It’s spelled with kanji as 水中. We can see from that then, the on’yomi for 水 is すい.

It’s like if “hydro-” and “aqua-” and “water-” were all written with the same symbol (let’s still use 水). A bunch of water-related words would use different readings (hydrodynamic, aquatic, watermelon), but they all would contain that same symbol when written out (水dynamic, 水tic, 水melon). Just so happens that the symbol would be “pronounced” differently depending on the word you’re saying.

This is also part of why some kanji will have multiple on’yomi (or even kun’yomi). Language is messy, people start mishearing or slurring or otherwise pronouncing stuff differently, but the writing stays the same, so the same character comes to represent multiple sounds. I’m oversimplifying a bit here but whatever :stuck_out_tongue:


Thank you! This reply is beginning to make sense of things for me (also a very new beginner).

I’ve been struggling to understand the apparent complexity, and I’m worried I’ve missed something. I expect kanji to be semantic, not syllabic. So if I see 水, I would think ‘What does that mean, and what’s the word for that meaning?’ I wouldn’t think, ‘How do I pronounce 水?’

So then when I see 水中, I would ask ‘What do those kanji mean together, and what’s the word for that thing?’

That seems completely reasonable, but again, have I missed something?

The article on Tofugu uses 木 as an example, and shows two ways of ‘reading’ it. And initially what that implied to me is that there are two words for tree, and only one of them is correct, based on context. But what I understand now (correctly?) is that no, there’s one word for tree, it’s just that 木 can be part of a compound kanji, the word for which may not include the pronunciation of ‘tree’. But of course it wouldn’t - it’s an entirely separate word.

I feel like I’m on the edge of insanity. Is my understanding more or less correct here? If so I think things have been made to seem more complicated than they actually are.

Thanks to anyone who helps me!


Yes, this is basically correct. Although, you can often figure out the reading of a compound word if you know the readings for the individual kanji - which is why WaniKani teaches those readings.

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The way you described it is often how it works. For the word tree with that kanji, there’s just き. There are actually more than two readings, but yes, the others are used in compounds.

That’s not always the case, but it’s generally how things go.

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Thank you Taschi and Leebo! I feel a little more sane now :slightly_smiling_face:

Fundamentally they’re semantic. Which is how you get exceptions like 今日 (today). At least WK told me it’s an exception; :sweat_smile: correct me if I’m wrong. But think about how many compound words in English share root words or affixes, where that piece has a consistent meaning and pronunciation in multiple words. Like Latin bi: bicycle, biped, bicentennial, and Greek di: dimorphism, dilemma. These being used despite English being well-equipped with the Germanic two. Kanji is a bit like if all of these words were written as 二cycle, 二morphism and just plain old 二. In this etymological thought experiment, two would be analogous to the kun’yomi, bi would be analogous to an old on’yomi, and di would be analogous to a very very old on’yomi from a dialect used under a totally different dynasty.

Basically modern Kanji is the spaghetti code you get by combining a bizarre writing methodology with many centuries of linguistic evolution and historical baggage. Kanji make more sense if you know Japanese, and it made a hell of a lot more sense if you knew* how to read Japanese* and Chinese during whichever century any particular word happened to be coined.


You’re not wrong.

(Note that 今日 can actually be read as “konnichi” or “konjitsu”, and those are not exceptions. But “kyō”, the reading you’d use in regular conversation, definitely is one.)

it made a hell of a lot more sense if you knew Japanese during whichever century any particular word happened to be coined.

No it wouldn’t: most of these problems do not stem from how Japanese has evolved over the ages, but from how the Chinese script was grafted onto a language that is fundamentally different from Chinese. And quite frankly, some of the oldest uses of kanji in Japanese writing will hurt your brain.


One useful comparison for me is that Chinese is in many ways to Japanese what Latin is to English.

In this respect you can compare みず and すい to “water” and “aqua”, respectively. You’ll only use the former when you ask for a glass of water, but you’ll see the latter in many (but not all!) compound words such as aquagymnastics or aquarium.


Wow this is a really great explanation actually!

You could also look at it with the words money and financial.
Imagine :heavy_dollar_sign: is a western kanji.
Then :heavy_dollar_sign: would be pronounced money, but also as finance, or economy
Readings of $ and $ary could be money and monetary.
While readings of $ial and $es could be financial or finances.
$ics or $ist would be economics or economist.

These readings all have different roots in different languages, similarly to the Kun’yomi and On’yomi in Japanese. Maybe in that way, it makes a bit more sense.


Yeah that was poor word choice on my part. What I was trying to say is that some of these words probably seemed like the best idea at the time with the tools available to a small class of literate academics who understood medieval Chinese and Japanese.

most of these problems do not stem from how Japanese has evolved over the ages, but from how the Chinese script was grafted onto a language that is fundamentally different from Chinese.

That’s what I was trying to imply, thanks for clarifying. At the time all the cool civilizations were doing it, and there was a certain utility the shared script, but then Japan got stuck with it, and continued to dig in deeper and deeper over the centuries.

The comparisons to Latin and Greek are really helpful, and I realise what I had in my head yesterday (and wrote above) still wasn’t correct. Thank you everyone for explaining it so well.

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