Radicals and kanjis

みず (mizu – water)

We already saw a set of radicals related to katakanas; some of those radicals are also katakanas, others are also kanjis, and some, like the radicals ニ, ハ, 匕, エ, ロ, and カ are both katakanas and kanjis. The majority of kanjis are not radicals, though, but instead are made up of simpler components. In this post we describe the relationship between a kanji and it’s radical, and discuss the way that kanjis are composed.

In the page introducing radicals we laid them all on the table, together with their variations. We saw that a radical is a set of strokes that has some ‘basic’ meaning. The 214 radicals were selected to index all characters, so every kanji either is a radical or contains a radical. In addition, if we include in the term ‘radical’ the few one-stroke CKJ characters that were not selected to be radicals, we can guarantee that we can decompose every kanji into a set of radicals, i.e., we can use radicals to study kanjis as if the kanjis had been designed as a synthesis of the radicals that form it.

Let’s take the case of a typical kanji: (na), which means ‘name’. For example, 名 is the 3rd character in the title of the blockbuster movie ‘kimi no na wa’ (your name?):

, or ‘name’, has two components:

  • radical #36, , which means ‘evening’ or ‘sunset’
  • radical #30, , which means ‘mouth’ or ‘opening’

An old technique to memorize kanjis is to come up with a mnemonic using its components; the popular books of “Remembering the Kanji” by Helsig use this approach. For example, we could concoct that the entrance (口) to Aladdin’s cave opens at sunset (夕), if we chant our name (名); we are not necessarily interested in figuring out how the meanings of 夕, or ‘evening’, and 口, or ‘mouth’, actually combine to give 名 its meaning of ‘name’. Actually, it is sometimes the case that the meaning of the kanji given by the combination of its components has been lost over the centuries.

Instead, what we care about is that the kanji 名 is composed completely of the two components 夕 and 口, which we can use to both remember the meaning of the kanji and figure out how to write it correctly. As long as the story is memorable, this method works even if we get the actual components wrong, e.g., if we decompose 名 into 夕, 冂, and 一, we can still come up with a mnemonic that might not be correct with respect to the original components of the kanji (that an etymologist would care about), but would still work perfectly well for the purpose of remembering the kanji and writing it correctly.

In this post we will decompose kanjis into their components: simpler kanjis, katakanas and radicals. In the term ‘radicals’ we are including a few CJK single-stroke characters. CJK is the collective name for the characters used in China, Japan, and Korea, all derived from the Chinese characters. These few CJK single-stroke characters were not selected as radicals because, although needed for character decomposition, were not needed for character indexing. As an aside, the methodology of composing all characters using a set of single-stroke characters is also used to create commputer fonts [CDL].

the kanji’s radical

Kanjis are combinations of components: simpler kanjis, radicals, and katakanas. Every kanji has one -and only one- radical, called ‘the kanji’s radical’, that gives the kanji its particular meaning (semantic component) or sound (phonetic component). For example, the kanji for fountain, 泉, has two components: the radical 白 (#106 – white) stacked on top of the radical 水 (#85 – water) (Jisho); the radical of 泉, used for its indexing in a radical-based dictionary, is 水, and it indicates that 泉 (fountain) has some fundamental relationship with 水 (water); although 白 (white) is also a radical that appears in 泉, if is not ‘the’ radical of 泉, so 白 counts only as a component of 泉.

There is no rule about what the radical of a kanji is. For example, we can surmise that the radical of 花 (flower) is one of its most visible radicals, i.e., it is either 艹 (#140 – grass), イ (#9 – person), or 匕 (#21 – spoon); indeed, the radical of 花 is 艹 (grass), which says that 花 has something to do with plants, and we will find its definition in the 艹 section of a radical-based dictionary.

Likewise, there is no rule for where in the kanji we will find its radical, although commonly it will be in one of its sides: on top, like in 花 (flower); at the bottom, like in 泉 (fountain); on the left, like in 泪 (tear); or on the right, like in 化 (change). In these cases, semantic radicals tend to appear on the left and top of the kanji, while phonetic ones tend to appear on the right and bottom. Another possibility is for the radical to surround the kanji, either partially or totally, like in 囚 (prisoner). Here are these kanjis, with their radicals in red:

Sometimes a radical is a kanji, like in 木, in which case, of course, the radical of the kanji is itself, e.g., the ‘tree’ radical, 木, is the radical of the ‘tree’ kanji, 木. The ‘tree’ radical is also the radical for the ‘grove’ kanji, 林, which has two parts: on the left, the ‘tree’ radical that gives the ‘grove’ kanji its ‘tree-related’ meaning, and on the right, a kanji that, in this case, coincidentally, happens to be the kanji for ‘tree’. The ‘tree’ radical is also the radical for the ‘forest’ kanji, 森, which has two parts: on the top, the ‘tree’ radical, which gives the ‘forest’ kanji its ‘tree-related’ meaning, and on the bottom the kanji for ‘grove’, 林. Hence, the ‘tree’ radical is the radical of the kanjis for ‘tree’, ‘grove’, and ‘forest’, and indicates that all these kanjis are related to trees:

a. tree – き; b. groove – はやし; c. forest – もり.

the kanji’s bounding box

All kanji fit within an imaginary square box. As shown above, the kanji 林 has the radical 木 and the kanji 木 side-by-side, so to fit them in the square box we have to squeeze them sideways, i.e., to make them thinner. On the other hand, the kanji 森 has the radical 木 on top of the kanji 林, so to fit them in the square box we have to squash them, i.e., to make them shorter.

We can still recognize the radical 木 regardless of whether we squeeze it or squash it, because 木 has a simple appearance and few strokes. However, a radical with many strokes is difficult to squeeze or squash, so it is often the case that such complex radicals would have one or two simpler versions, with less strokes. For example, the radical for ‘water’, 水, has the alternate form ⺡. Both 水 and ⺡ have identical meanings, but we will use 水 when we are stacking the radical, and ⺡ when we are squeezing it horizontally:

water – みず

fountain – いずみ

simplified radical
water – みず

tear – なみだ

Some radical varations, by design, have a specific shape that helps them fit in the bounding box. Vertical thin radicals, like “water”, ⺡, are always on the left or right of the kanji, while horizontal short radicals, like “grass”, ⺾, are always stacked:


flower – はな

potato – いも

seedling – なえ

A radical doesn’t necessarily need to have a small number of strokes; instead, a simple concept might require a large number of strokes; regardless, these many-stroke kanjis still need to fit within a same-size bounding box. Not many few-stroke radicals are also kanjis, but most many-stroke radicals are. An example is the radical for ‘rain’, 雨, with 8 strokes, which is also the kanji for ‘rain’; the ‘rain’ radical is the radical of the kanjis for ‘cloud’, ‘thunder’, and ‘snow’, among many others:

rain – あめ

cloud – くも

thunder – かまきり

snow – ゆき

Oat milk

Plant-based-milk kanji (Oatly Asia Campaign)

The Swedish oat-milk company ‘Oatly’ picked up on the way characters are composed to come up with a new ‘character’ for their publicity campaign in East Asia (greenqueen, campaignasia). In Chinese, we write cow-milk with two characters, as 牛奶, where 牛 means ‘cow’ and 奶 means ‘milk’.

Oatly reasoned that they could describe ‘plant-based milk’ by composing a new character: start with 牛奶 for ‘cow milk’, then remove the character 牛 for ‘cow’ and, finally, add the radical ⺾ for ‘plant’. The result is

This is not an official character; we would not be able to find it in a dictionary, nor there is a way to type it, nor a way to pronounce it. Still, its visual meaning as ‘plant-based milk’ would be clear to anyone that can read these characters and radicals, so it makes sense as a way to raise awareness and introduce the product. Characters, indeed, are made up of simpler components, and we can decompose them as a way to help us memorize them and write them in the correct order and with the correct strokes. Good luck to ‘Oatly’ on their quest for a more sustainable planet.

stroke order vs. component order

Every kanji is either a radical, or has a radical; if it has a radical, we can remove it and be left with a simpler character that we can break into simpler kanjis and radicals; if we so desire, we can repeat this process until we are left with only a single-stroke component.

When we write a component in a kanji, usually we write it completely before moving on to a different component of the kanji; there are exceptions, like the surrounding radicals like ‘enclosure’, 囗, for which we write the components contained inside the radical before closing the bottom of the radical. However, in most cases, we write each component of the kanji completely before moving to the next component. Thus, learning the order of strokes of components of kanjis helps us write all kanjis based on those components.

Consider the kanji for ‘flower’, 花. The radical of 花 is ‘grass’ or ‘vegetation’, 艹; if we remove it, we are left with the kanji for ‘change’, 化. The radical of 化 is ‘spoon’, 匕; when we remove it, we are left with the radical for ‘person’, ⺅. Hence:

English Kanji radical Kanji minus radical

Kanjis, in general, are written from top-to-bottom and/or from left-to-right. Hence, to write the kanji for flower, 花, we just need to write its three parts 艹, ⺅, and 匕, in that order, from top-to-bottom and/or left-to-right. As long as the strokes for each individual component are correct, the strokes for the complete kanji are likely to be correct, e.g., the following are the strokes for 花, for which we write each component completely before moving to a different component:

The kanji 花 is its radical 艹, and the kanji 化. The kanji 化 is its radical 匕 and the radical ⺅

Hence, instead of specifying each stroke of the kanji, we can simply specify its radical and components, and the order in which we should write each of them, e.g., if we know the stroke order of the 艹, ⺅, and 匕 radicals, and/or the 化 kanji, we can describe the stroke order of 花 describing the order in which we should write its components:

花 = 艹⺅匕; or 花 = 艹化; either one works fine