Katakana characters come from fragments of kanjis; in many cases, the monks that created these characters took from the kanji, as the fragment, exactly the set of strokes that centuries later would become one of the 214 radicals. Let’s look again at the kanjis on which the katakana characters are based, but focusing on the fragment of the kanji that was used to create the character:

Many katakana characters, like メ(me) and ラ (ra), were created from fragments that didn’t have a meaning; however, some katakana characters, marked below in green, are very close to the radicals they came from, while others, marked in blue, still preserve from the radicals they came from both a resemblance and the stroke order. These are easy radicals to learn because we already know them as katakana characters, so all we need is to learn their meanings as radicals.

katakanas = radicals

The following katakana characters are also radicals. In some cases, the radical that became a katakana character has additional forms, in which case, we can find them below. For example, the radical/katakana イ, which means ‘man’ or ‘human’, also has the alternative form 人. Since all these katakana characters and radicals are slight variations of each other, they tend to share their stroke order.

katakanas ⇐ radicals

Sometimes the monks based a katakana character on a set of strokes that would become a radical, but the present form of the character is not identical to the radical. Such set of radicals is also easy to learn because, even if the katakana character and the radical are not identical, they still resemble each other and their stroke order is the same.

katakanas ⇒ radicals

Finally, there are some katakana characters that resemble radicals from which they were not based, and that share the stroke order.

getting to know them

We have identified some radicals that are easy to learn because they are either identical or similar to a katakana character, and they share the stroke order. Organized by radical number they are:

Free radicals

Free radicals are those that never show up by themselves. From our radicals and their variations, they are:

The stroke order of most of the radicals above is the standard left-to-right top-to-bottom. The components of any character – radical or kanji – are simpler radicals and kanjis, and katakana and CKJ single-stroke characters; Here are the components of some of them:

radicals that are katakanas

Now let’s go over the radicals that are also katakanas; their stroke order is the same as the stroke order of the corresponding katakana, which we already saw, so we won’t repeat it here.

radicals that are kanjis

And now, a bonus. Some of these radicals are also kanjis. In some cases, like in カ or ロ, a character is a radical, a katakana, and a kanji. However, the common case is that a radical that is also a kanji is not a katakana, like 人 or 川. We might interpret a character differently depending on whether we are using it as a radical or as a stand-alone kanji; for example, ニ means ‘two’ both as a radical and as a kanji, but 又 means ‘hands’ as a radical, while it means ‘again’ as a kanji. We have already described the meanings of these characters as radicals, so below we describe their meaning as kanjis, which might or might not be the same.

The only occurrance of 乀 that I have found is in 丿乀 (へつぽつ), which means ‘to rock from side to side’; not a very common character, ね? 🤔 It does not appear as one of the official one-stroke kanjis so I am not sure what to make of it.

Here is the decomposition of some of these kanjis, particularly of those that are not katakanas or that don’t have the standard left-to-right top-to-bottom order:

And, just like that, we have 30 radicals and their variants under our belt.

CJK single-stroke characters

In the sections above, we decomposed some free radicals and kanjis using only radicals and the single-stroke character ㇆, which is not a radical. Indeed, ㇆ is not one of the 214 characters selected to index all other characters, but it still is part of some characters; we find it – and a few others non-radical single-stroke ideograms – in the most comprehensive list of characters: the CJK list.

The Chinese-Japanese-Korean unified ideographs, a.k.a. the CJK, is a comprehensive list of all the Chinese characters and their variants used in any of these languages. All these characters are based on a set of CJK single strokes. Since we can compose any character using them, it follows that we can decompose any character into them.

In the CJK, ㇆ is called the HZG stroke; the name encodes the turns of the stroke. All these strokes are in the unicode table, so we can write them with a computer. Some of the CJK strokes that were not selected as radicals, together with their unicodes, are:

We will encounter these non-radical single-stroke CJK characters from time to time, but we will treat them as if they were radicals. Hence, if we run across a one-stroke character that is not a radical, we now know where to find it. 😊 👍