On'yomi and Kun'yomi Readings
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.