Radicals (or in Japanese, ぶしゅ 部首) are the roots which kanji are made up of. Every single kanji in the Japanese language has at least one radical.
Now you can get by without learning these radicals, but when you begin learning similar kanji it begins to get difficult to distinguish the differences between them, and you will wish you had at least a basic understanding of radicals.
So, let’s take for example, the following 3 kanji (all N4 level):
The following kanji all have the radical for 寺 in them (on the right), which means “temple”. But each one has a different starting radical (on the left).
時 – The left radical of this kanji is 日 (sun, day, time). The meaning of this kanji is “time”. So sun + temple = time
詩 – The left radical of this kanji is 言 (words, to speak, say). The meaning of this kanji is “poetry, poem”. Say + temple = poetry
持 – The radical of this kanji is 扌(hand). The meaning of this kanji is “to hold”. Hand + temple = hold
Each one is very similar and the only distinguishing item is their radical. As you can see, knowing the radicals help you remember the meaning of the kanji itself as they are often (but not always) linked to the kanji’s meaning.
For those who have read (or at least heard of) Heisig’s Remembering the Kanji, this might begin to sound familiar.
Heisig’s Remembering the Kanji…
This is a book which teaches English speakers how to understand the meanings of kanji. Not the Japanese reading or compounds, just the individual kanji and their English meanings.
This is because, Heisig argues, Chinese people have an advantage over English speakers as they already know the meanings of kanji and can therefore guess what is happening in a text based on this. Learning the meanings to kanji gives English people the same advantage that Chinese people have naturally.
How Heisig teaches you the meanings for kanji is through radicals and mnemonics. Mnemonics are memory devices which play on words and sounds to help you remember words or phrases.
For example, the as mentioned kanji “poem”, which Heisig tries to help you remember through a story, referencing previous kanji learnt:
In other words, you build up your understanding of kanji through their meanings, based on other kanji and their radicals that you’ve learnt.
I think Heisig’s method is very interesting to read, but it’s not a book for everyone. Some people enjoy studying hard using it, others will just read it. But it is interesting how he builds up the kanji based on their radicals, and it begins to help you distinguish the relationships between complex kanji and their meanings.
Back to radicals…
There are 7 categories of radicals all of which are based on their positions within the kanji (as you can see in the image below):
Japanese people learn these too!
As you may have noticed each position and each radical also has a Japanese name.
Japanese students will have to learn these positions and the radical names in school. There’s even a test in Japan for Japanese people on kanji called the Kanji Kentei, which covers radicals as well as individual kanji readings and kanji compounds! Unlike the JLPT, however, this is a hand written test, so you also need to know writing and stroke order!
It’s a very hard test that even Japanese people struggle to pass. Although there are foreigners who have been masochistic enough to take and pass the test! (See this Youtube video for example – all in Japanese).
How to Learn Radicals
You can learn radicals, as mentioned, through their English meanings. There’s even a Memrise Japanese Radicals Course made by someone else which helps with this.
The Japanese Kanji Study app on android teaches you radicals via English and Japanese names. And you can test yourself and practice writing them! It also shows how each kanji is broken down by their radicals! The radicals and beginners kanji levels are free, but you need to pay for advanced (N4 to N1) kanji.
You can also learn them by learning the kanji through other kanji and mnemonics, i.e the Heisig method.
You can learn them like a Japanese native and study their Japanese names (and the kanji they’re used in).
Beyond this there are not many resources online for practicing radicals.
My advice is to learn the English meanings to help you remember (even read through Heisig’s book), but study the radicals with their Japanese names. (Japanese Kanji Study app on Android is the best for this)
This is because they will reveal a lot more about Japanese as a language (such as “stick” in English literally means “stood up stick” in Japanese, which then teaches you the Japanese for “stood up stick” たてぼう). It also helps if you want to talk to Japanese people, and can open up a whole new way of learning kanji as you can get Japanese people to describe the kanji to you through radicals.*
TL;DR – Reasons You Should Learn Radicals:
- Helps recognize differences in similar kanji
- Helps you remember kanji meaning
- Useful if you enjoy studying kanji (i.e want to take high JLPT and/or the Kanji Kentei)
- Learn the radicals using their Japanese names, but read (but don’t focus too much) Heisig to help memorize their meanings and the kanji related to them.
Resources for Learning Radicals & Using them:
Japanese Kanji Study – Android app, free to learn radicals.
Kanji Alive – List of all kanji by their categories, including Japanese and English names for them
Memrise Japanese Radicals Course – Only teaches you the radicals and their English meanings
Heisig’s Remembering the Kanji – DL pdf of all 3 of his books
Radicals Kanji Cheat-sheet by Tofugu – Radical and English meaning