I don’t completely get the difference between vocabulary readings and kanji readings. I understand that there’s kun’yomi and on’yomi and that kanji expresses concepts (and that they can be used for/have several concepts and readings), but how does WaniKani decide which reading to choose for vocab vs kanji? how, historically, are these chosen? and is knowing which one simply a matter of memorization?
Any help/resources would be appreciated!
Kanji are a bit like letters while vocabulary are words made out of letters. For instance consider the word ‘book’. The first letter is b and conveys the b sound. The sound for the word ‘book’ begins with a b. Similarly the kanji conveys sounds that are found in vocabulary containing the kanji.
The sounds are not chosen by any rule or logic. They are the result of centuries of evolution of the language. This is similar to the sounds for the language of English that are the result of the language evolution.
There are some rules of thumb that can be helpful. For instance
All these rules have exceptions, so be careful about that.
For the history behind all this you can read this article.
I don’t know if it helps, but I found this on the Knowledge Guide:
Kanji can have multiple readings: on’yomi readings and kun’yomi readings.
On’yomi readings originated from China and are sometimes called the “Chinese readings” of kanji.
Kun’yomi readings originated in Japan and are sometimes called the “Japanese readings” of kanji.
Both of these readings are important when it comes to learning kanji and reading words in Japanese. You should definitely give our On’yomi and Kun’yomi Guide a read. It explains the history of these readings, information on how to use them, and some handy tips and tricks when you aren’t sure.
In general, compound words (two or more kanji put together) use the on’yomi readings, while kanji with hiragana attached use the kun’yomi readings. Single kanji can use either. (And of course there are plenty of exceptions, which our lovely mnemonics will help you with.)
WaniKani almost always teaches the on’yomi reading with the kanji. Then you’ll learn kun’yomi readings later, with vocabulary words.
Sometimes you’ll also see a kanji with Nanori readings, or “name readings.” These are special readings used for Japanese names.
I think Wanikani doesn’t choose the readings per se, it just tries to make you learn one or two most useful readings per kanji and acquire the other readings naturally through vocabulary study.
Give the links of the Knowledge Guide above a read! They will explain it better than me and I might be wrong since I haven’t been around that much.
The readings for vocab are simply the readings of the actual words as spoken, so what you would hear in japanese conversation or when a japanese person would read those words aloud in a text. (In a few cases the reading is context-dependent, but that is then explained in the mnemonic).
For the kanji readings there is no hard and fast rule for what Wanikani chooses. They typically use the reading(s) that they think will best aid your learning. Often that will be on’yomi, as that will help you predict the reading of future compound words. But if that kanji doesn’t have many compound words or they are all high-level/rare, they might teach kun’yomi reading(s) with the kanji instead.