Radicals are the building blocks of kanji, the once Chinese characters that are used as one of the three writing systems in Japan today. While you may be familiar with the term "radical" many people don't really know what they are or how to find the radical within a kanji that determines its arrangement and organization.
If you're a WaniKani user, you need to know that these aren't the same types of radicals that you're learning. This is the official (read: traditional) system used in dictionaries and taught in Japanese schools. While WaniKani teaches you useful mnemonics to piece together and understand what kanji are made of, finding the radical is a different process.
Before we dive in, you should already be familiar with kanji stroke order. Being able to recognize the number of strokes in a kanji is essential for what we're about to go over. If you ever want to use a traditional or electronic dictionary, have proper Japanese handwriting, and/or practice shodo 書道 (calligraphy), proper stroke order is a must.
What is a Kanji Radical?
Radicals, known in Japanese as bushu 部首, are a way to classify characters in order to find them in a list or collection. Sometimes they can help you figure out the meaning of the kanji, but most of the time they're just there to help you find out where they are. Radicals have their own nicknames in Japanese to help understand them, but even most Japanese people can't name them all from memory.
The Kangxi Radicals
First, let's look at how the radicals are categorized. The Kangxi radical system is a set of 214 radicals that are used to classify all of the kanji used in Japanese. Many Japanese character dictionaries are arranged by this system, instead of the Japanese Syllabary Order (gojuuonjun 五十音順), also known as AIUEO Order (あいうえお 順), which some beginner kanji dictionaries and vocabulary dictionaries use.
The Kangxi name comes from the original Chinese dictionary that standardized the system of classification back at the beginning of the 18th century, the Kangxi Dictionary (koukijiten 康煕字典). Though the idea of arranging characters by their 214 unique radicals was initially introduced a century earlier in the Zihui Dictionary (字彙), it wasn't until the Kangxi Dictionary that the system became widely accepted. The Zihui Dictionary was also the first to sort characters by their stroke order.
Radicals are generally broken up into categories based on that number of strokes. For instance, the lowest number of strokes a radical can have is one, and there are six different unique radicals that can have one stroke. The highest number of strokes a radical can have is seventeen, and there is only one, the radical 龠 (flute).
Why are Radicals Important?
You may be wondering why learning about the Kangxi radicals and how to find the radical is important. While the Kangxi radical system isn't the only existing list of radicals, it is widely used by almost all Japanese – English Character Dictionaries, including online dictionaries.
If you're trying to look up a character and you don't know the meaning or pronunciation, and you don't have electronic dictionaries or smartphones to draw what you see, the last option you have is to find the radical(s) and look it up that way.
Understanding and identifying radicals is a great skill to have and the more you practice, the more familiar you get with them, the easier looking up new kanji gets.
Not Everything is a Radical!
One of the misconceptions I've run into is people thinking that all radicals are kanji in themselves. While there are plenty of characters where the radical is also a kanji, it isn't universally true. It's like saying that all letters are words because it works for the letter "I". However, radicals like 凵 may be found in kanji like 凶 (bad luck) and 出 (exit), but 凵 isn't a character, it's just a radical.
While there seem to be arguments online about this, not every part of a character is a radical either. At least, not in the official sense. Yes, there are kanji made up of two or more radicals like 杉 (cedar) which is made up of the radicals 木 and 彡 (We'll go over how to determine which one is the radical it's classified under a little later on) but not everything is so cut and dry. For example, in the kanji 頂 (summit) the portion on the left is not a radical. The only radical here is 頁. Have another example: In the kanji 学 (learning) that top part? Not a radical. The only radical here is 子. How can I say they aren't radicals? Well they aren't listed within the 214. So while, yes, those other pieces also make up the character, they aren't officially radicals. (Remember that this is for classification purposes – those extra bits are still important to the kanji, just not if you're trying to find out where they are in a list.)
Radicals were not made up to help you learn Japanese. If they were, there would probably be enough to cover all the parts that make up a character. Again, they're the pieces of the kanji that Chinese scholars recognized and used to help with categorization. Don't sit down and memorize all 214 radicals and expect to know Japanese. The official radicals and their nicknames aren't meant to help you figure out what a kanji means. What a shame.
Modified Radicals
Radicals also don't always look the same in every situation. There are radicals that take different forms if you put them on top, to the left, or on the bottom portion of a character. Here are all the radicals that have variations:
| Radical | Variant(s) |
|---|---|
| 乙 | ⺄ 乚 |
| 人 | 亻 𠆢 |
| 刀 | 刂 |
| 卩 | 㔾 |
| 小 | ⺌ ⺍ |
| 尢 | 尣 |
| 巛 | 川 巜 |
| 彐 | 彑 |
| 心 | 忄 ⺗ |
| 戶 | 户 戸 |
| 手 | 扌 龵 |
| 攴 | 攵 |
| 无 | 歺 |
| 歹 | 母 ⺟ |
| 毋 | 氺 氵 |
| 水 | 灬 |
| 爪 | 爫 |
| 爿 | 丬 |
| 牛 | 牜 ⺧ |
| 犬 | 犭 |
| 玉 | 玊 王 ⺩ |
| 疋 | ⺪ |
| 示 | 礻 |
| 竹 | ⺮ |
| 糸 | 糹 |
| 网 | 罒 ⺲ 罓 ⺳ |
| 羊 | ⺶ ⺷ |
| 老 | 耂 |
| 聿 | ⺻ |
| 肉 | ⺼ |
| 艸 | 艹 |
| 衣 | 衤 |
| 襾 | 西 覀 |
| 言 | 訁 |
| 走 | 赱 |
| 足 | ⻊ |
| 辵 | 辶 ⻌ ⻍ |
| 邑 | 阝 ⻏ ⻖ |
| 金 | 釒 |
| 長 | 镸 |
| 阜 | 阝 |
| 青 | 靑 |
| 面 | 靣 |
| 風 | 𠘨 |
| 食 | 飠 |
| 高 | 髙 |
Some of them are fairly simple and don't change very drastically, but as you can see there are some that do. It's easy to get tripped up looking for a radical and realizing later that you were trying to look up at variant the whole time.
The Seven Radical Locations
There are seven different locations where you can find the radical of a character. If the radical uses a variation, the main version is next to it in parentheses.
| Image | Location | Examples |
|---|---|---|
 |
Hen 偏 – Left Side | 氵(水) in 海,扌(手) in 指,訁(言) in 記 |
 |
Tsukuri 旁 – Right Side | 刂(刀) in 利, 力 in 助, 欠 in 歌 |
 |
Kanmuri 冠 – Top | 艹 (艸) in 花, in 雨 in 雪, 穴 in 空 |
 |
Ashi 脚 – Bottom | 心 in 恋, 灬(火) in 点, 儿 in 免 |
 |
Tare 垂 – Northwest | 厂 in 原, 尸 in 局, 广 in 店 |
 |
Nyō 繞 – Southwest | ⻌(辵) in 近, 走 in 起, 廴 in 建 |
 |
Kamae 構 - Enclosure | 門 in 開, 囗 in 国, 勹 in 包 |
There are also a few kamae variants:
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The Twelve Steps to Finding the Radical
Now that you know where the radicals can be, the hard part is in finding which radical is the radical, or rather, the radical it will be categorized under. Luckily, there are twelve almost easy steps to finding the radical. They are as follows:
1. Is the whole character the radical?
The most obvious, and yet sometimes the most difficult to find, are the ones that are radicals themselves. For example, 人, 文, 長, and 黍 are all kanji where the whole thing is the radical.
2. Does it only have one radical?
Sometimes there is only one radical in the character. 乃 only has the radical 丿, and 了 only has the radical 亅.
3. Is there an enclosure?
If you find a character that has a radical covering 2 – 4 sides, that's usually the radical. In 気 the radical is 气, in 医 the radical is 匚, in 図 the radical is 囗.
4. Is there an obvious radical on the left?
The left radical should have nothing above or below it, and should not be intersecting with anything on the right. In 板 the radical is 木, in 銀 the radical is 金. Note that the parts of the characters that are on the right side are not radicals.
5. What about on the right?
This is the same as the last one, but on the opposite side. In 形 the radical is 彡, and in 欧 the radical is 欠.
6. How about on top?
Many top radicals look like slanted roofs. In 家 the radical is 宀, and in 奈 the radical is 大.
7. Okay, try the bottom?
These can be tricky, but remember if there are two or more parts on top, the radical might be on the bottom. In 楽 the radical is 木, and in 劈 the radical is 刀.
Now is the point where you only continue if you tried all of the other steps and still couldn't find the radical.
8. Northwest?
If we look at the character 報 there is a lot going on. The left and right sides are not radicals by themselves. So we look northwest, or top left, first, and see that the radical is 土.
9. Northeast?
So there was nothing in the northwest, how about northeast, or top right? In 呉 the only part that is a radical is 口.
10. Southeast?
You can't find anything at the top, so move down from where you were. In 君 we once again find the radical to be 口.
11. Southwest?
Last weird direction. Move back to the bottom left and sometimes the radical will be there. Look at this character 糶 – all of these corners are radicals! So you take the bottom left, 米.
Here, have an easier one, 虱 is not an enclosure radical because that top part isn't a radical at all. 虫 is the radical.
12. Okay, I give up, is it on the inside?
You don't have to wait until you've gone through all of the other steps to see these. In 夾 the radical is 大, in 県 the radical is 目, and in 嬲 the radical is 女.
Remember if there are two radicals in the same position, always go with the one with the higher number of strokes. Also, make sure the part you're picking is actually one of the 214 Kangxi radicals. Sometimes the first thing you pick might look like it's right because of its position, but if it isn't one of the 214, then it's technically not a radical, and you won't be able to find it because the section you're looking for doesn't exist!
Nelson's method is not the only way you can find the radical, in fact many character dictionaries have their own methods. Sometimes there are modifications made in order to fit the way the dictionary organizes it's radicals, so make sure when you're using a new one to take a look at their guide just in case there are any differences.
Missing Radicals
Unfortunately (and fortunately for us language learners), thanks to kanji simplification by the Japanese government, some kanji lost their radicals. The solution was to give them new radicals, but that doesn't make them any easier to find.
Let's look at two examples:
| Traditional Form | Traditional Radical | Simplified Form | New Radical |
|---|---|---|---|
| 兩 | 入 | 両 | 一 |
| 會 | 日 | 会 | 人 |
You can see why they had to change the categorization of these kanji. The problem is when you're trying to find the simplified version of a character and all you have is the traditional version to go by. Luckily, if you have a good dictionary you can still look up the old character and it will reference the newer, simplified version.
The Most Common Radicals
The following is a list of some of the most frequently used radicals out of the 214. It can be helpful to become familiar with at least this list and their variants, but you really don't have to memorize them by any means. I've also included their English nicknames, but they aren't official, just helpful when trying to understand what you're looking at.
| Radical | Reading | Nickname |
|---|---|---|
| 一 | いち | one |
| 丨 | ぼう | rod, line |
| 丶 | てん | dot |
| 丿 | の | slash, kana no |
| 亠 | なべぶた | lid |
| 人 (亻,𠆢) | ひと | man |
| 八 | はちがしら | eight |
| 刀 (刂) | かたな | sword, knife |
| 十 | じゅう | cross, ten |
| 厂 | がんだれ | cliff |
| 口 | くち | mouth |
| 囗 | くにがまえ | box, enclosure |
| 土 | つち | earth |
| 女 | おんな | woman |
| 宀 | うかんむり | roof, kana u |
| 小 (⺌, ⺍) | しょう | little, small |
| 尸 | しかばね | flag, corpse |
| 山 | やま | mountain |
| 巾 | はば | cloth, turban |
| 广 | まだれ | dotted cliff |
| 弓 | ゆみ | bow |
| 彳 | ぎょうにんべん | going man, step |
| 心 (忄,⺗) | りっしんべん | heart |
| 手 (扌,龵) | て | hand |
| 攴 (攵) | ぼくづくり | folding chair, rap |
| 日 | にち | sun |
| 木 | き | tree |
| 水 (氺,氵) | みず | water |
| 火 (灬) | ひ | fire |
| 牛 (牜, ⺧) | うし | cow |
| 犬 (犭) | いぬ | dog |
| 玉 (玊, 王, ⺩) | たま | jewel, jade |
| 田 | た | rice field, field |
| 疒 | やまいだれ | sick, sickness |
| 皿 | さら | dish |
| 目 | め | eye |
| 石 | いし | stone |
| 示 (礻) | しめす | showing, spirit |
| 禾 | のぎ | two branch tree, grain |
| 立 | たつ | stand, standing |
| 竹 (⺮) | たけ | bamboo |
| 米 | こめ | rice |
| 糸 (糹) | いと | thread, silk |
| 耳 | みみ | ear |
| 肉 (⺼) | にく | meat |
| 舟 | ふね | ship, boat |
| 艸 (艹) | くさ | grass |
| 虫 | むし | bug, insect |
| 衣 (衤) | ころも | clothes, clothing |
| 見 | みる | see, seeing |
| 言 (訁) | ことば | speech, speaking |
| 貝 | かい | small shell |
| 足 (⻊) | あし | foot |
| 車 | くるま | cart, car |
| 辵 (辶,⻌,⻍) | しんにょう | road, walk |
| 邑 (阝,⻏,⻖) | むら | city, right village |
| 金 (釒) | かね | metal, gold |
| 門 | もん | gate |
| 阜 (阝) | おか | left village, mound |
| 隹 | ふるとり | old bird, short tailed bird |
| 雨 | あめ | rain |
| 頁 | おおがい | big shell, leaf |
| 食 (飠) | しょく | eat, food |
| 馬 | うま | horse |
| 魚 | うお | fish |
| 鳥 | とり | bird |
Now that you know all about radicals, why don't you put your new knowledge to the test in a kanji dictionary? Good luck!