By Linguipixie
Reading Chinese characters can be difficult already, since you need to memorize both the meaning and the pronunciation of a character, but Japanese characters (kanji) definitely take it to the next level: indeed, most Japanese characters have at least two different pronunciations, sometimes three, four, up to ten and even more. In order to read Japanese, one must therefore be able to recognize the character and its meaning, but also its various possible pronunciations, and then, deduce which pronunciation is the right one, based on context. So here’s a short (non-exhaustive) guide to reading kanji!
On-yomi and kun-yomi: origin story
Kanji pronunciations can be broken down in two main categories (with a few exceptions): the Japanese pronunciations (seems logical) called ‘kun-yomi’ and the pronunciations of Chinese origin called ‘on-yomi’. This can be explained by looking at the history of writing in Japan.
The first script used in Japan was the Chinese script, i.e. Chinese characters, but the language that was transcribed was not yet Japanese: basically, the first Japanese texts were actually written in Chinese. Of course, the Chinese characters didn’t cross the Sea of Japan on their own, they came in the form of texts imported from the continent (carried by Korean migrants who knew how to read and write Chinese). Those texts contained many words and concepts that were new to the Japanese mind and were incorporated into the Japanese language as such in writing, and in the oral language by japanizing their original Chinese pronunciation. Chinese being an isolating language, most words are composed of one or two syllables and a character transcribes one syllable, while Japanese words are usually longer and can have flexional endings, so those Chinese lexical items, even with their japanized pronunciation, probably stood out a bit.
Then, the Japanese decided to start transcribing their own language and did so through the only script they knew of: Chinese characters. The characters were therefore assigned the Japanese pronunciation corresponding to their meaning: for instance, 木 represents a “tree” and is therefore assigned the Japanese pronunciation for “tree” = “ki”1; 森, which represents a forest is assigned “mori” = “forest”, etc. All this seems quite simple and straightforward so far, even though one character could now transcribe several syllables2 instead of just one in the Chinese system. However, remember that Japanese also had Chinese loan words which already had their own characters. For instance, the word 木材, which is composed of the character for “tree” and the character for “material” and means “timber” is pronounced “mokuzai”. 木 therefore has two pronunciations: the Japanese reading “ki” and the reading of Chinese origin “moku”. Welcome to a learner’s hell!
On-yomi and kun-yomi: when to use which
So how can we know which pronunciation is the right one in a given context? Well, it can be rather complex, especially when a kanji has several on-yomi (see next paragraph to understand how this happened), but in general, it’s down to context:
If a kanji stands alone in a text, it is most likely transcribing a Japanese lexical item, so the ‘kun-yomi’ applies;
If, on the contrary, the kanji is part of a compound (usually 2 kanji together but it can be more), chances are it’s a Chinese loan word and ‘on-yomi’ applies… unless it’s a given name, in which case it’s probably ‘kun-yomi’ (because Japanese names are… Japanese words, duh!).
However, this is only a general guideline, as you also might encounter the occasional stand-alone Chinese loan word, as well as Japanese compound words, and there also exists combinations of kun- and on-yomi within a compound word (on-kun compound readings are called “jûbako” (“jû” in this word being on-yomi and “bako” being kun-yomi) and kun-on compound readings are called “yutô” (guess what’s what!)).
Basically, the only way to know how to pronounce a Japanese character is to actually recognize the word it is part of (and to know this word already). In case you know the character but have never seen the word, please refer to the rules above and statistically you shouldn’t be wrong very often.
Why so many on-yomi??
To put a cherry on top of this fascinating mess, it is rather common for a Japanese character to have several on-yomi (and occasionally several kun-yomi as well). This is due to the political history of China. Indeed, Chinese texts were imported in Japan in several waves, but in between waves, Chinese dynasties changed, were conquered by a neighbour or whatever, and the oral language of the Chinese court changed, while the writing system remained the same, Chinese characters. The latter were therefore assigned new pronunciations, but the Japanese basically kept integrating Chinese load words in the same way as before: taking the written word and japanizing its Chinese pronunciation. Therefore, characters that had already been imported as part of one word decades or centuries before could be imported again as part of another loan word with a different pronunciation assigned to it in this specific context. On-yomi are therefore categorized according to the Chinese dynasty in power when they came to exist in Japan:
呉音 “go-on” are the first pronunciations that were imported, from the kingdom of Wu (in Chinese, or Go in Japanese); those texts were mostly related to Buddhism so many Buddhist terms in Japanese have “go-on-yomi”;
漢音 “kan-on” are from the Tang dynasty and often relate to Confucianism;
宋音 “sô-on” are from the Song and Yue dynasties and often relate to Zen Buddhism;
唐音 “tô-on” are from the Ming and Qing dynasties.
1 All the examples are from modern day Japanese.
2 Japanese is usually divided in moras rather than syllables but the difference is not significant in this article.