What is the significance of a repeated radical in a Kanji character?

Question

What is the significance (if any) of a repeated radical in a Kanji character?

I have been learning Kanji for almost a year now. In the early days my assumption would have been that repeating a radical would emphasise quantity/intensity/scale in an intuitive way such as with the following characters:

木 林 森

Now I am starting to come across Kanji with repeated radicals where the meaning (at least to me) isn't as obvious. I notice they almost always appear as adjacent pairs.

談 態 曜 歌

Answer 1

In general, don't overinterpret repeated components. It's inconsistent and largely a hit-and-miss exercise.

Sometimes they just mean "lots of" the single repeated component, or some extended meaning from that. For example, in addition to 「木」->「林」->「森」, there is

• 「火」(fire) ->「炎」(blaze)
• 「屮」(sprouting plant, not used as an individual character) ->「艸」(full character form of 艹, grass radical)
• 「人」(person) ->「衆」(crowd; the bottom was actually originally 3「人」, as can be seen in the Taiwan variant「眾」)
• 「𠂇」(right hand, top left component of「右」) ->「友」(friend, two right hands)
  • Note that「又」was also originally a picture of a right hand; the meaning again/also is a phonetic loan, and had nothing to do with the character itself.)
• 「一」->「二」->「三」(trivial example)
• There are also plenty of Chinese-only examples that I won't mention here.

Other times, they don't have anything in particular to do with the whole character, like all the rest of your examples.

• 「[談]{だん}」is just a word meaning to discuss that has a semantic component「言」and a phonetic component「[炎]{えん}」.
  • There was an ancient variant「譚」that meant and was pronounced exactly the same as「談」; neither「譚」nor「談」, nor other characters which use「炎」as a phonetic component, such as「[淡]{だん}」(dilute) or「[毯]{たん}」(carpet), have anything to do with fire.
• 「[態]{た​い}」(manner; c.f. [態度]{た​いど}, attitude) has a semantic component「心」and a phonetic component「能」, which had a very ancient alternative pronunciation of「ない」.
  • The repeated component「匕」doesn't actually contribute to the meaning of「能」at all, because「能」(ability) was originally a phonetic loan, and cannot be broken down; the original character was a full-fledged picture of a type of bear, where「匕」was the bear's legs:
    
  • Bear is now written「熊」to differentiate the character from the meaning of ability.
• 「曜」just has a semantic component「日」and a phonetic component「翟」.
  • 「翟」had an Old Chinese pronunciation *lˤewk, while for「曜」, The pronunciation evolved in accordance to /*lewk-s/ (Old Chinese) -> /jiᴇuʰ/ (Middle Chinese) -> よう (Japanese On'yomi).
  • The repeated component「习」cannot be separated from「羽」, which was originally a picture of feathers.
  • 「翟」originally referred to a type of bird:
    
• 「[歌]{か}」just has a semantic component「欠」and phonetic component「[哥]{か}」.
  • 「欠」was originally a depiction of a person with an open mouth:
    
    The meaning to lack is an extension from the original meaning. Other characters which feature「欠」as a semantic component include 吹 (to blow) and 歎 (to sigh, variant of 嘆).
  • 「哥」itself is an ancient variant of「歌」and is no longer used for the meaning song. It is a reduplication of「[可]{か}」, which also originally meant song, but very early on shed this meaning and took on the role of a phonetic loan for can, be able to, permissible. These original meanings of「哥」and「可」were entirely lost through the course of history, and you shouldn't view「哥」as "lots of 可".

Answer 2

What you are referring to are called 理義字. Radicals containing more strokes are more likely to emphasize quantity/intensity/scale as you have mentioned: 轟 (roaring), the sound of many carriages. 昌(clear) and 晶(crystal) follow a similar pattern.

For 談, the two 火 together indicate burning. Together with 言 they would indicate 'hot conversation' or 'discourse'.

Some 理義字 are merely simplified from the original kanji to repeat the same radical with no further meaning. Others, such as 曜, used to mean something else (a flying bird next to the sun = bright), and later came to represent the contemporary meaning.

This might be a bit above my ability to explain properly. I would just suggest that sometimes they can be read more literally, sometimes they have evolved from more literal meanings, and sometimes they are simple representations of more complex Chinese characters.