Kun’yomi and on’yomi are the readings of the kanji – on’yomi are pronunciations borrowed from Chinese, while kun’yomi are the pronunciations of the original Japanese words that existed before the kanji was given to it. For example, 犬, the kanji for dog, has いぬ as its kun’yomi and けん as its on’yomi (note that on’yomi are usually written in katakana in dictionaries, so you can tell which is which). けん comes from the Chinese pronunciation of 犬 – in modern Chinese it’s “quan”, so you can kind of see the similarity. いぬ is the original Japanese word for “dog” which already existed before Chinese writing came to the country. 犬 is read as いぬ when it’s standing on its own, and けん when it’s standing with other kanji (for example, 猛犬 = もうけん = vicious dog). Of course, there’s always exceptions – one notable one is 子犬, which is read as こいぬ.

Every rule in Japanese has exceptions. Including this one.

Hiragana tacked onto the end of kanji (for verb and adjective conjugations and whatnot) is called “okurigana”. These exist basically because verbs and verb conjugations existed in Japanese long before Chinese writing arrived. Essentially, almost all verbs and い-adjectives are of Japanese origin. Kanji with attached okurigana always, always use the kun’yomi – no exceptions. This is the exception to the “all rules have exceptions” rule. =)

For example, 走る – to run. The る is okurigana, and the kanji 走 takes its kun’yomi, はし. When you conjugate the verb, you change the okurigana, i.e. 走る－走らない－走った－走らなかった and so on. Also, 走ります－走りません et cetera.

coclans wrote:

Just like you read 1 as “one” and 1st as “first”, and not “onest”.

Ooo. I like that. Kinda like the animal is a “cow” but the meat is “beef” – the former comes from Saxon, while the latter comes from French.