How do I know when to use which reading for a kanji?

When I got to the vocabulary from lesson one, all the different readings and where to use them got really confusing. For example, the kanji 大 can be pronounced たい, だい, or おお, but how do I know when to use which reading in a vocabulary word, and why was I only taught たい and だい when learning the kanji by itself? In future, should I learn Kun’yomi in addition to the On’yomi when learning a kanji? Is there some pattern I’m missing? Thanks so much in advance!


A general rule of thumb is vocab that has two or more kanji’s combined will use the on’yomi reading, and vocab with only one kanji, or one kanji and some hiragana, will use kun’yomi. Of course there are many exceptions, but many follow this rule. As far as things like たい becoming だい readings also change due to rendaku. There are rules for this as well but they are very complicated and it’s easier just to memorize when rendaku occurs in certain words.

Here’s some helpful articles:


WaniKani focuses on only one or two of the most common readings when you learn the kanji so that you don’t get overwhelmed while still giving you a good starting point for guessing readings of vocab. I believe it still shows you the other readings in the lesson somewhere. Some kanji have dozens of readings that should really only be learned as part of the vocab they appear in.

1 Like

Learning the words is the long term solution. Experience. You will start to be able to predict readings with “better than random chance” accuracy once you learn enough words.


On rendaku, the good news is that later on you’ll just start feeling when it is likely to happen.

When I started learning I had a Japanese friend tell me “it’s just easier to say it that way”. A lot of the times the rendaku happens in order to make the word sound smoother or easier to say. Once I started thinking of them as shortcuts and focusing on how hard or easy it was to voice the sound (like how much my tongue had to move) they started to feel a lot easier to guess.

I know this answer isn’t as satisfying as “memorize these rules”, but if you work hard it will happen.


honestly, at beginner level, there’s just no way to tell, and trying to figure it out is a waste of time and calories. just do the vocab and don’t worry. it’s exactly as Leebo said, you’ll get there naturally, over time.

This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.