Kanji Radicals: What They Are and the Most Useful Ones to Learn
By the Kantan JLPT team · · 9 min read
Quick answer: A radical is the part of a kanji that dictionaries use to group and look it up, and it often hints at the kanji's meaning. For example, 氵 means water, so it shows up in 海 (sea), 池 (pond) and 泳 (swim). There are 214 traditional radicals, but learning the 20 or so most common ones is enough to make new kanji far easier to remember.
When you first see a kanji like 語 or 働, it can look like a random cluster of lines. Once you know its parts, it becomes a few familiar pieces. This article explains what radicals are, where they appear in a kanji, and which ones are worth learning first. For the bigger picture, including how many kanji you need for each level, see our complete guide to learning kanji for the JLPT.
What is a kanji radical?
Most kanji are built from smaller parts. Learners often call any of these parts a component. One component of each kanji is its radical (部首, bushu), the part that dictionaries use to sort characters.
The traditional system has 214 radicals. Each kanji is filed under exactly one of them. The kanji 休 (rest), for example, is filed under the person radical 亻, and 林 (grove) is filed under the tree radical 木.
Many radicals are also kanji on their own: 木 (tree), 口 (mouth), 日 (sun), 女 (woman). Others change shape when they become part of another kanji. 水 (water) turns into 氵 on the left side, 人 (person) becomes 亻, and 手 (hand) becomes 扌.
In everyday study, learners use "radical" and "component" loosely and interchangeably, and that's fine. What matters is recognizing the parts.
Where do radicals appear in a kanji?
A radical can sit in different positions. Japanese has names for each position, and these names show up in Japanese dictionaries and in the names of the radicals themselves.
| Position | Japanese name | Where it is | Examples |
|---|---|---|---|
| Left side | へん (hen) | Left part of the kanji | 亻 in 休, 氵 in 海 |
| Right side | つくり (tsukuri) | Right part of the kanji | 頁 in 頭 and 顔 |
| Top | かんむり (kanmuri) | Like a crown on top | 艹 in 花, 宀 in 家 |
| Bottom | あし (ashi) | Underneath, like legs | 心 in 思, 灬 in 点 |
| Top and left | たれ (tare) | Hangs over from the top left | 广 in 店, 疒 in 病 |
| Left and bottom | にょう (nyō) | Wraps around the bottom left | 辶 in 道, 走 in 起 |
| Enclosure | かまえ (kamae) | Surrounds the rest | 門 in 間, 囗 in 国 |
Knowing the positions helps you describe a kanji to yourself ("person on the left, tree on the right") and find it in a dictionary.
The 20 most useful radicals to learn first
These radicals appear in many common kanji and usually give a real hint about meaning. Every example below is filed under the radical shown.
| Radical | Name | Meaning | Example kanji |
|---|---|---|---|
| 亻 (人) | にんべん | person | 休 (rest), 体 (body), 何 (what), 住 (live) |
| 氵 (水) | さんずい | water | 海 (sea), 池 (pond), 洗 (wash), 泳 (swim) |
| 木 | きへん | tree, wood | 林 (grove), 森 (forest), 校 (school), 橋 (bridge) |
| 口 | くち / くちへん | mouth | 味 (taste), 呼 (call), 吸 (inhale) |
| 言 | ごんべん | speech, words | 話 (talk), 語 (language), 読 (read), 説 (explain) |
| 扌 (手) | てへん | hand | 持 (hold), 打 (hit), 押 (push), 指 (finger) |
| 艹 | くさかんむり | grass, plants | 花 (flower), 茶 (tea), 草 (grass), 薬 (medicine) |
| 宀 | うかんむり | roof, house | 家 (house), 室 (room), 安 (cheap, safe), 寒 (cold) |
| 日 | ひへん / にちへん | sun, day | 明 (bright), 晴 (clear weather), 時 (time), 暗 (dark) |
| 女 | おんなへん | woman | 好 (like), 妹 (younger sister), 姉 (older sister), 始 (begin) |
| 糸 | いとへん | thread | 紙 (paper), 線 (line), 終 (end), 結 (tie) |
| 金 | かねへん | metal, gold | 銀 (silver), 鉄 (iron), 鉛 (lead) |
| 心 / 忄 | こころ / りっしんべん | heart, feelings | 思 (think), 忘 (forget), 忙 (busy), 情 (emotion) |
| 辶 | しんにょう | movement, road | 道 (road), 近 (near), 遠 (far), 送 (send) |
| 雨 | あめかんむり | rain, weather | 雪 (snow), 雲 (cloud), 電 (electricity), 雷 (thunder) |
| 食 / 飠 | しょく / しょくへん | food, eating | 飲 (drink), 飯 (meal, rice), 館 (large building) |
| 門 | もんがまえ | gate | 開 (open), 閉 (close), 間 (interval) |
| 力 | ちから | power, strength | 動 (move), 助 (help), 勉 (make an effort) |
| 土 | つちへん | earth, soil | 地 (ground), 場 (place), 坂 (slope) |
| 火 / 灬 | ひへん / れっか | fire | 焼 (burn, grill), 灯 (lamp), 点 (point), 熱 (heat) |
A few things to notice:
- The meaning link is often clear. 泳 (swim) has water, 持 (hold) has a hand, 花 (flower) has grass, 雪 (snow) has rain.
- Sometimes the link is loose or historical. 電 (electricity) sits under rain because it originally related to lightning. 館 (large building) is under food, which is usually explained by its old meaning of a guesthouse where visitors were given meals and lodging. 間 (interval) is under the gate radical. These still help you remember the shape, even if the meaning isn't obvious.
- Some names repeat. Both 日 and 火 can be called ひへん in Japanese, so the sun radical is often called にちへん instead to avoid confusion.
How do radicals help you learn kanji?
They make kanji easier to remember
Remembering 18 separate strokes is hard. Remembering "speech on the left, plus a few familiar parts on the right" is much easier. Radicals let you break a complex kanji into chunks, which is how memory works best.
They also power mnemonics. 休 (rest) is a person leaning against a tree. 好 (like) is a woman with a child. 明 (bright) is the sun and the moon together.
They help you guess meanings
When you meet an unfamiliar kanji, the radical often tells you the general area. A new kanji with 氵 probably relates to water or liquid. One with 言 probably relates to language or speaking. One with 扌 probably describes something you do with your hands. It won't give you the exact meaning, but it narrows things down.
They help you tell look-alikes apart
Many kanji share most of their shape and differ only in the radical. 持 (hold, with the hand radical) and 待 (wait, with a radical meaning "going") look similar, but the left side tells you which is which. The same goes for 話 (talk) and 活 (activity), which share the right side but have different radicals.
They help you look up kanji
If you see a kanji you can't read, you can find it by its radical:
- Radical index: Paper and many digital dictionaries list radicals by stroke count. You find the radical, then look for your kanji among those filed under it, sorted by the number of remaining strokes.
- Component search: Many digital dictionaries let you pick several components you can see, and they show matching kanji. This is usually the fastest method, and it works even if you don't know which part is the official radical.
- Handwriting input: You can draw the kanji on your phone. Knowing basic stroke order helps the recognizer get it right.
One caution: the official radical isn't always the most obvious part. 聞 (hear) looks like it belongs under 門 (gate), but dictionaries file it under 耳 (ear). That's another reason component search is so handy.
Common mistakes with radicals
- Trying to memorize all 214 radicals first. Many are rare. Learn the common ones above, and pick up others as they appear in kanji you study.
- Expecting the radical to give the exact meaning. It's a hint, not a definition. 校 (school) has the tree radical, but it doesn't mean "tree."
- Confusing similar radicals. 氵 (water, three strokes) and 冫 (ice, two strokes) look alike, as do 亻 (person) and 彳 (going). Count the strokes.
Frequently asked questions
How many kanji radicals are there?
The traditional system used in most dictionaries has 214 radicals. Some modern dictionaries adjust the list slightly, but 214 is the standard number.
Do I need to learn radicals for the JLPT?
The JLPT doesn't test radicals directly. But radicals make kanji much easier to remember and tell apart, which helps with kanji reading and orthography questions at every level.
Should I learn radicals before kanji?
You don't need to finish radicals before starting kanji. Learn the most common radicals early, ideally alongside your first N5 and N4 kanji. Many basic kanji, like 木, 口, 日 and 女, are radicals themselves, so you'll learn several just by studying the JLPT N5 kanji list.
Do radicals tell you how a kanji is read?
Not usually. Radicals mostly hint at meaning. Many kanji also contain a component that hints at the on'yomi, but that's a different part from the radical, and the hint isn't always reliable. For how readings work, see on'yomi vs kun'yomi.
Build kanji from parts with Kantan JLPT
Kantan JLPT helps you learn kanji alongside the vocabulary they appear in, from N5 to N1, with spaced-repetition reviews that bring back the kanji you miss. Spotting the radicals in each new kanji is a simple habit that makes those reviews easier, and it pays off more with every level you climb.