Learn kanji readings in words
A kanji’s reading list gives possibilities. The word and its context determine the reading you use.
What on and kun readings mean
On readings developed from borrowed Chinese pronunciations; kun readings associate a kanji with a Japanese word of corresponding meaning. One character can have several readings.
The Korean meaning-and-reading label is a memory aid, not a Japanese pronunciation. Learn the kana reading of the Japanese word separately.
Do not decide from spelling alone
Compounds often use on readings, while words with following hiragana often use kun readings, but these are clues, not rules. Learn whole-word readings such as 一人（ひとり）and 乙女（おとめ）.
Study an unfamiliar word as a set: spelling, kana, meaning, and an example. Substituting the first on reading into every word can produce the wrong pronunciation.
Practice with Kotomoa
Open a related word after checking the readings on a kanji detail page. Cover its reading, say it aloud, then compare it with the example.
Save confusing kanji and words in a review folder. Separate spelling-to-reading practice from understanding a word in context so you can identify the gap.
Quick check: Can you always read 一人 as いちにん?
Show the answer and why
No. The basic reading for one person is ひとり. Learn the word’s reading rather than assembling it character by character.