Radicals are 214 well-defined sets of strokes that have a ‘basic’ meaning. For example:

All the examples above are both radicals and kanjis; however, not all radicals are kanjis, e.g., the radical 亻, which like 人 means ‘person’ or ‘human’, is not a kanji. Usually, if a radical is a kanji, they mean the same thing: 口 and 目 mean ‘mouth’ and ‘eye’, respectively, both as radical and kanji; there are exceptions, though: 方 means ‘square’ as a radical, but means ‘direction’ or ‘person’ as a kanji, while 首 means ‘head’ as a radical, but means ‘neck’ as a kanji. Radicals that are not kanjis are called ‘free radicals’ and only show up as components of a more complex character, e.g., the human legs radical 儿, the plant radical 艹, the long stride radical 廴, and many others.

Although a kanji may be composed of many radicals, only one of those radicals gives it its general meaning, or ‘flavor’; this one radical becomes the kanji radical of that kanji; all other radicals become components. Thus, we can classify any kanji according to its kanji radical. Actually, radicals were originally selected to classify and index the kanjis in the kangxi dictionary, published in 1716. Still today, some Japanese and Chinese dictionaries are organized by radicals.

Besides being able to use radical-based dictionaries, learning radicals is useful because they are the building blocks of all kanjis. We can view kanjis as a random set of meaningless strokes, and learn them the hard way, by repetition, or we can view them as an organized set of components, each one adding some meaning to the kanji, which is much easier.

singling out radicals

We often refer to the radicals by number. In the tables below, the number of a radical in a given row and column, i.e., (row, column), is

radical No. = (row × 10) + column

Thus, for example, the radical for ‘mountain’, 山, is in (4,6), i.e., row 4, column 6, so it is radical 46, and the radical for ‘water’, 水, is radical 85, so we will find it in (8,5), i.e., row 8, column 5.

The following are the 214 kangxi radicals, ordered by their number of strokes (wikipedia, unicode):

Overwhelming? Yes… at first sight. However, they are a huge help in understanding and writing kanjis and, unlike the kanas, there is no good reason to learn them all at once.

radical variants

Although there are only 214 radicals, many show up in different forms or variations that resemble each other [WP]. For example, we can find the radical #9, which means ‘person’ or ‘human’, written as 人, or its variants 亻, 𠆢, or 𠂉. Thus, a better table of reference for radicals would include these variations:

	0	1	2	3	4	5	6	7	8	9
0		一	丨	丶	丿乀 乁𠂉	乙乚 ⺄乛	亅	二	亠	人亻 𠆢𠂉
1	儿	入	八ハ 丷	冂⺆	冖	冫⺀	几⺇	凵	刀⺈ ⺉	力
2	勹	匕	匚	匸	十	卜⺊	卩⺋	厂⺁ 丆	厶	又
3	口	囗	土	士	夂	夊	夕	大	女	子
4	宀	寸	小⺌ ⺍	尢⺎ ⺏⺑	尸	屮	山	巛川 巜	工	己⺒ 已巴
5	巾	干	幺	广	廴	廾	弋	弓	彐⺔ ⺕ヨ	彡
6	彳	心⺖ ⺗	戈	戶戸 户	手扌 龵	支	攴⺙	文	斗	斤
	0	1	2	3	4	5	6	7	8	9
7	方	无⺛	日⺜	曰	月⺝	木朩	欠	止	歹歺	殳
8	毋⺟	比	毛	氏⺠	气	水⺡ ⺢	火⺣	爪⺤ ⺥	父	爻
9	爿⺦	片	牙	牛⺧ 牜	犬⺨	玄	玉⺩ 王	瓜	瓦	甘
10	生	用	田	疋⺪	疒	癶	白	皮	皿	目⺫
11	矛	矢	石	示⺬ ⺭	禸	禾	穴	立	竹⺮	米
12	糸⺯ ⺰	缶	网⺱ ⺲⺳ ⺴⺵	羊⺶ ⺷⺸	羽	老⺹	而	耒	耳	聿⺺ ⺻
13	肉⺼	臣	自	至	臼⺽	舌	舛	舟	艮	色
	0	1	2	3	4	5	6	7	8	9
14	艸⺾ ⺿⻀ 䒑	虍⻁	虫	血	行	衣⻂	襾⻃ ⻄	見⻅	角⻆ ⻇	言⻈ 訁
15	谷	豆	豕	豸	貝⻉	赤	走赱	足⻊	身	車⻋
16	辛	辰	辵⻌ ⻍⻎	邑⻏	酉	釆	里	金⻐ 釒	長⻒ ⻓	門⻔ 门閂 闩
17	阜⻕ ⻖	隶	隹	雨⻗	靑⻘	非	面靣	革	韋⻙	韭韮
18	音	頁⻚	風⻛	飛⻜	食⻞ ⻟⻠	首⻡	香	馬⻢	骨⻣	高
19	髟	鬥	鬯	鬲	鬼	魚⻥	鳥⻦	鹵⻧	鹿	麥⻨
20	麻	黃⻩	黍	黑黒	黹	黽⻪	鼎	鼓	鼠鼡	鼻
21	齊⻫ ⻬	齒⻭ ⻮	龍⻯ ⻰	龜⻱ ⻲⻳	龠
	0	1	2	3	4	5	6	7	8	9