what is the logic for assigning Kanji characters to certain radicals?


Why is 富 character under 宀 40th radical? why isn't it under 102nd radical 田 ?

Why is 仏 character under 人 9th radical? why isn't it under 28nd radical 厶 ?
etc.

what is the logic for assigning Kanji characters to certain radicals?




In principle, it's arbitrary. Dictionary makers are free to put 富 under
whichever section they want, and the same goes for 仏 or any other character.
And in fact, editors of some dictionaries put characters under different
radicals; see for example the New Nelson. As such, they can have different
motivations, and it's impossible to answer what the motivation is in every
case.

However, 富 fits a very common pattern: like the majority of kanji, it can be
divided into a semantic component and a phonetic component. In such cases, the
semantic portion is _usually_ the radical. In this character, 宀 is the
semantic portion, while 畐 is the phonetic portion.

Likewise, 仏 consists of 亻 and 厶. The former is the semantic and the radical,
and the latter is the phonetic.

There are other patterns you can recognize. For example:

  * If a character is itself a radical, it is its own radical.
  * Semantic-phonetic characters are generally divisible into two parts. In your example of 富, it's not likely for 田 to be the radical because the top half doesn't form a character, so the division is probably somewhere else (in this case, just under 宀).
  * In left-right kanji, the left side is much more likely to be the radical.
  * In top-bottom kanji, the top side is more likely to be the radical.
  * In enclosure kanji, the enclosure is more likely to be the radical.
  * The left-side radical form of 人, called にんべん, is written 亻. If a character contains this element, it's most likely the radical! This is true of many such combining forms, including `氵`, `灬`, `忄`, and so on.

In some cases, you'll simply have to memorize the radicals. For example, 謄, 騰,
and 勝 and all have 朕 as a phonetic! So the radicals are in the unexpected
lower-right position, and you'll find these characters under 言, 馬, and 力. As
you come to recognize phonetic elements and identify them with patterns in
音読み, identifying radicals like these will be easier, and over time, you'll
simply come to remember them.

(In principle, you can tell that the radical is in lower-right position in the
above because those kanji aren't left-right divisible, but in practice this is
difficult because (for example) valid left and right sides may include
characters that are no longer used or were never used in Japanese.)

And there will always be exceptions to the above generalizations. For example,
the kanji 錦 has the same _on_ reading as its left side (金), so it appears that
the phonetic portion is on the left. But in this case, that's also the
radical! Why? Well, the right side can't be the radical simply because it's
not one of the 214 choices! Likewise, the radical for 難 is on the right. Why?
Again, the left side isn't one of the 214!

So it's a complicated system, and it's likely to surprise you. But hopefully
the more you learn, the more it will make sense, and the rest you'll be able
to memorize or look up as need be. (After all, it is just a system for
indexing dictionaries.)




In principle, it's arbitrary. Dictionary makers are free to put 富 under
whichever section they want, and the same goes for 仏 or any other character.
And in fact, editors of some dictionaries put characters under different
radicals; see for example the New Nelson. As such, they can have different
motivations, and it's impossible to answer what the motivation is in every
case.

However, 富 fits a very common pattern: like the majority of kanji, it can be
divided into a semantic component and a phonetic component. In such cases, the
semantic portion is _usually_ the radical. In this character, 宀 is the
semantic portion, while 畐 is the phonetic portion.

Likewise, 仏 consists of 亻 and 厶. The former is the semantic and the radical,
and the latter is the phonetic.

There are other patterns you can recognize. For example:

  * If a character is itself a radical, it is its own radical.
  * Semantic-phonetic characters are generally divisible into two parts. In your example of 富, it's not likely for 田 to be the radical because the top half doesn't form a character, so the division is probably somewhere else (in this case, just under 宀).
  * In left-right kanji, the left side is much more likely to be the radical.
  * In top-bottom kanji, the top side is more likely to be the radical.
  * In enclosure kanji, the enclosure is more likely to be the radical.
  * The left-side radical form of 人, called にんべん, is written 亻. If a character contains this element, it's most likely the radical! This is true of many such combining forms, including `氵`, `灬`, `忄`, and so on.

In some cases, you'll simply have to memorize the radicals. For example, 謄, 騰,
and 勝 and all have 朕 as a phonetic! So the radicals are in the unexpected
lower-right position, and you'll find these characters under 言, 馬, and 力. As
you come to recognize phonetic elements and identify them with patterns in
音読み, identifying radicals like these will be easier, and over time, you'll
simply come to remember them.

(In principle, you can tell that the radical is in lower-right position in the
above because those kanji aren't left-right divisible, but in practice this is
difficult because (for example) valid left and right sides may include
characters that are no longer used or were never used in Japanese.)

And there will always be exceptions to the above generalizations. For example,
the kanji 錦 has the same _on_ reading as its left side (金), so it appears that
the phonetic portion is on the left. But in this case, that's also the
radical! Why? Well, the right side can't be the radical simply because it's
not one of the 214 choices! Likewise, the radical for 難 is on the right. Why?
Again, the left side isn't one of the 214!

So it's a complicated system, and it's likely to surprise you. But hopefully
the more you learn, the more it will make sense, and the rest you'll be able
to memorize or look up as need be. (After all, it is just a system for
indexing dictionaries.)

