Radical (Chinese characters)

In the earliest Chinese dictionaries, such as the Erya (3rd century BC), characters were grouped together in broad semantic categories. Because the vast majority of characters are phono-semantic compounds (形聲字), combining a semantic component with a phonetic component, each semantic component tended to recur within a particular section of the dictionary. In the 2nd century AD, the Han dynasty scholar Xu Shen organized his etymological dictionary Shuowen Jiezi by selecting 540 recurring graphic elements he called bù (部 , "categories").[3] Most were common semantic components, but they also included shared graphic elements such as a dot or horizontal stroke. Some were even artificially extracted groups of strokes, termed "glyphs" by Serruys (1984, p. 657), which never had an independent existence other than being listed in Shuowen. Each character was listed under only one element, which is then referred to as the radical for that character. For example, characters containing 女 nǚ "female" or 木 mù "tree, wood" are often grouped together in the sections for those radicals.

Mei Yingzuo's 1615 dictionary Zihui made two further innovations. He reduced the list of radicals to 214, and arranged characters under each radical in increasing order of the number of additional strokes – the "radical-and-stroke-count" method still used in the vast majority of present-day Chinese dictionaries. These innovations were also adopted by the more famous Kangxi Dictionary of 1716. Thus the standard 214 radicals introduced in the Zihui are usually known as the Kangxi radicals. These were first called bùshǒu (部首, literally "section header") in the Kangxi Dictionary.[3] Although there is some variation in such lists – depending primarily on what secondary radicals are also indexed – these canonical 214 radicals of the Kangxi Dictionary still serve as the basis for most modern Chinese dictionaries. Some of the graphically similar radicals are combined in many dictionaries, such as 月 yuè "moon" and the 月 form (⺼) of 肉 ròu, "meat, flesh".

After the writing system reform in Mainland China, the traditional set of Kangxi Radicals became unsuitable for indexing Simplified Chinese characters. In 1983, the Committee for Reforming the Chinese Written Language and the State Administration of Publication of China published The Table of Unified Indexing Chinese Character Components (Draft) (汉字统一部首表（草案）).[4] In 2009, the Ministry of Education of the People's Republic of China and the State Language Work Committee issued The Table of Indexing Chinese Character Components (GF 0011-2009 汉字部首表), which includes 201 principal indexing components and 100 associated indexing components[5] (In China's normative documents, "radical" is defined as any component or 偏旁 piānpáng of Chinese characters, while 部首 is translated as "indexing component".[6]).

Radicals may appear in any position in a character. For example, 女 appears on the left side in the characters 姐, 媽, 她, 好 and 姓, but it appears at the bottom in 妾. However, there are two radicals that have the shape 阝, but are indexed as different radicals depending on where they appear. When used with the abbreviated radical form of 邑 yì "city" it gives 都 dū "metropolis", also read as dōu "all-city" it appears on the right, but when used with the abbreviated radical form of 阜 fù "mound, hill" (as in 陸 lù "land") it appears on the left. However, there are regularities in the positioning next to ("within") most characters, depending on function: semantic components tend to appear on the top or on the left side of the character; similarly, phonetic components tend to appear on the right side of the character or at its bottom.[7] These are loose rules, though, and exceptions are plenty. Sometimes, the radical may span more than one side, as in 園 = 囗 "enclosure" + 袁, or 街 = 行 "go, movement" + 圭. More complicated combinations exist, such as 勝 = 力 "strength" + 朕—the radical is in the lower-right quadrant.

Many character components (including radicals) are distorted or changed to fit into a block with others. They may be narrowed, shortened, or may have different shapes entirely. Changes in shape, rather than simple distortion, may result in fewer pen strokes. In some cases, combinations may have alternates. The shape of the component can depend on its placement with other elements in the character.

Some of the most important variant combining forms (besides 邑 → 阝 and 阜 → 阝per the above) are:

• 刀 "knife" → 刂 when placed to the right of other elements:
  • examples: 分, 召 ~ 刖
  • counter-example: 切
• 人 "man" → 亻 on the left:
  • 囚, 仄, 坐 ~ 他
  • counter-example: 从
• 心 "heart" → 忄 on the left:
  • 杺, 您, 恭* ~ 快

(*) 心 occasionally becomes ⺗ when written at the foot of a character.

• 手 "hand" → 扌 on the left:
  • 杽, 拏, 掱 ~ 扡
  • counter-example: 拜
• 水 "water" → 氵 on the left:
  • 汆, 呇, 沊 ~ 池
  • counter-example: 沝
• 火 "fire" → 灬 at the bottom:
  • 伙, 秋, 灱 ~ 黑
  • counter-example: 災
• 犬 "dog" → 犭 on the left:
  • 伏, 状 ~ 狙
  • counter-example: 㹜

Many dictionaries support using radical classification to index and lookup characters, although many present-day dictionaries supplement it with other methods as well. For example, modern dictionaries in PRC usually use the Pinyin transcription of a character to perform character lookup. Following the "section-header-and-stroke-count" method of Mei Yingzuo, characters are listed by their radical and then ordered by the number of strokes needed to write them.

The steps involved in looking up a character are:

1. Identify the radical under which the character is most likely to have been indexed. If one does not know, then the component on the left side or top is often a good first guess.
2. Find the section of the dictionary associated with that radical.
3. Count the number of strokes in the remaining portion of the character.
4. Find the pages listing characters under that radical that have that number of additional strokes.
5. Find the appropriate entry or experiment with different choices for steps 1 and 3.

For example, consider the character 信 xìn, meaning "truth", "faith", "sincerity", and "trust". Its radical is 亻 rén "human" (a compressed form of 人) and there are seven additional strokes in the remaining portion (言 yán, "speech"). To look up this character in a dictionary, one finds the radical for "human" in the part of dictionary that indexes radicals. The various radicals will be organized by the number of strokes they themselves contain. 人 and its compressed version 亻 contain only two strokes, so it will be near the beginning of the list. Locating it, one can see the page for the index on that radical, and one then normally passes through the lists of characters with one additional stroke, two additional strokes, etc. until one reaches the entries with seven additional strokes. If the chosen radical matches the radical used by the dictionary compiler (which can be difficult to guarantee for more complicated characters), and if both the user and the dictionary compiler count strokes the same way (also often a problem with characters that the user is unfamiliar with), the entry will be in that list, and will appear next to an entry number or a page number where the full dictionary entry for that character can be found.

As a rule of thumb, components at the left or top of the character, or elements which surround the rest of the character, are the ones most likely to be used as radical. For example, 信 is typically indexed under the left-side component 人 instead of the right-side 言; and 套 is typically indexed under the top 大 instead of the bottom 長. There are, however, idiosyncratic differences between dictionaries, and except for simple cases, the same character cannot be assumed to be indexed the same way in two different dictionaries.

In order to further ease dictionary lookup, dictionaries sometimes list radicals both under the number of strokes used to write their canonical form and under the number of strokes used to write their variant forms. For example, 心 can be listed as a four-stroke radical but might also be listed as a three-stroke radical because it is usually written as 忄 when it forms a part of another character. This means that the dictionary user need not know that the two are etymologically identical.

It is sometimes possible to find a single character indexed under multiple radicals. For example, many dictionaries list 義 under either 羊 or 戈 (the radical of its lower part 我). Furthermore, with digital dictionaries, it is now possible to search for characters by cross-reference. Using this "multi-component method"[19] a relatively new development enabled by computing technology, the user can select all of a character's components from a table and the computer will present a list of matching characters. This eliminates the guesswork of choosing the correct radical and calculating the correct stroke count, and cuts down searching time significantly. One can query for characters containing both 羊 and 戈, and get back only five characters (羢, 義, 儀, 羬 and 羲) to search through. The Academia Sinica's 漢字構形資料庫 Chinese character structure database[20] also works this way, returning only seven characters in this instance. Harbaugh's Chinese Characters dictionary[21] similarly allows searches based on any component. Some modern computer dictionaries allow the user to draw characters with a mouse, stylus or finger, ideally tolerating a degree of imperfection, thus eliminating the problem of radical identification altogether.

• Chinese character description languages
• List of kanji radicals by stroke count
• List of kanji radicals by frequency

• Luó Zhènyù (羅振玉) 1958. 增訂殷墟書契考釋 (revised and enlarged edition on the interpretation of oracle bone inscriptions). Taipei: Yiwen Publishing (cited in Wu 1990).
• Serruys, Paul L-M. (1984) "On the System of the Pu Shou 部首 in the Shuo-wen chieh-tzu 說文解字", in 中央研究院歷史語言研究所集刊 Zhōngyāng Yánjiūyuàn Lìshǐ Yǔyán Yánjiūsuǒ Jíkān, v. 55:4, pp. 651–754.
• Xu Shen Shuōwén Jǐezì (說文解字), is most often accessed in annotated versions, the most famous of which is Duan Yucai (1815). 說文解字注 Shuōwén Jǐezì Zhù (commentary on the Shuōwén Jíezì), compiled 1776–1807, and still reproduced in facsimile by various publishers. The reproduction by 天工書局 Tiāngōng Books (1998) in Taipei is useful because the seal characters are highlighted in red ink.

Look up Index:Chinese radical in Wiktionary, the free dictionary.

Wikimedia Commons has media related to radicals and their variants in regular script.

Wikimedia Commons has media related to the 214 Kangxi radicals.

Wikimedia Commons has media related to the 540 Shuowen radicals.

• Chinese Character Radicals List of Chinese Character Radicals
• 汉语大词典部首表 a list of radicals in the Hanyu Da Cidian