You just have to commit it to memory. Most of the radicals that Wanikani uses are made up. There aren’t that many in general. They are probably better to think of as kanji parts. Wanikani uses them to create mnemonics to aid in remembering the kanji better.
If you come up with your own that is more effective, then I say use that. As long as you’re remembering and learning you’re accomplishing the goal.
I understand what the radicals are for and that the naming is somewhat arbitrary, but given two possible radical compositions, when you look at the kanji by itself and you don’t know its parts, can you tell that noon would be a slide and an antenna and not a gun and a cross?
You can’t balance a gun on a cross. It slides down and makes cow: 牛.
So are kanji unique with regards to their radical compositions? 
I don’t know if WK actually takes care to that extent with the smaller parts, but obviously conflicts begin when you start replacing bunches of radicals with combo radicals. You are just expected to recognize 㐮 is “nurse”, and not the “six”, “blackjack”, and “clothes” radicals that make that radical up. But the mnemonics really only need to get you to guru or master level and then you can forget them.
I think I get what you’re asking! It’s possible for two different kanji to be made out of the same radicals, but the kanji still won’t look the same, thus each kanji is unique regardless of its radical composition. For instance, flat object counter (枚) and clause (条) both use the same radicals (tree and winter), but they’re in different positions!
Of course that just opens another can of worms where WK is a bit sloppy with some things, since they aren’t teaching writing. The two non-tree parts of those two kanji aren’t the same part. They have different numbers of strokes and come from different precursor elements. 枚 uses this 攵 and 条 uses this 夂.
If you look at this image, you’ll see what I’m asking: https://cl.ly/kS5T
I know it’s slide + antenna (right hand side) because I memorized it. But if I didn’t know it, how would I know It breaks up into slide and antenna and not gun and cross?
Granted the closest answer is from Heiopei, as from what I understand, in this case, cross and gun are in the same relative place to each other in both places, and that’s not unique. I understand that radicals in different positions will make different words.
There’s no way to “know” why it’s one and not the other, because WK is just making shit up as they go, so if they wanted to make it gun and cross they could. But they didn’t *shrug*
Hm… Also this http://jisho.org/search/午%20%23kanji seems to suggest it could be either radical compositions?
Lists both with slide and ten as radical parts.
Pretty much. There’s no defined standard for “kanji parts.”
Hm… so a while ago I read that pretty much all kanji are made up of radicals, and even if you don’t know the actual meaning of the kanji (because you forgot, haven’t come across it, etc…) you can usually figure it out by context and / or knowing its radical parts.
That’s one of those things that is true in a handful of really easy to point out situations like 森 being forest because it’s a bunch of trees. After that small handful of things, the vast majority of the 3000 or so kanji that appear in native materials don’t have any logical connection between the elements that make them up and their meanings.
Occasionally radicals will offer hints at meaning, like ones with the tree radical often being related to plants, the water radical (tsunami here) usually relates to water, and the hand radical (called nailbat here) is usually about grabbing or other physical actions. But the exceptions are also numerous.
Oh, and my favorite one of those is the moon radical is actually commonly associated with body parts, because it’s an adaptation of the meat kanji.
Additionally, “radicals” in a strict sense, the way they are defined for kanji dictionaries, are just the main kanji part for any given kanji. Each kanji only has one radical. So unless a kanji and its radical are one in the same, which happens frequently with simple ones, it’s made up of more than just “radicals.”
Ah, hm… That’s good to know Thank you
I guess then my plan is: get some working vocab and familiarity with a bunch of kanji (WK seems good for this), get conversational and reading japanese going, and then delve into the intricacies of grammar / writing possibly revisiting existing knowledge.
Oh, and the same thing applies to vocab. Just knowing the kanji base meanings can give you a hint if you’ve never seen the word before, but the fact that you can do kanji combo reversals and get new words proves that just knowing the meanings alone isn’t enough. For example 会社 (company) and 社会 (society).
Oh yup. Ran into it with princess 王女 and queen 女王 already
It’s a good idea to learn collocations rather than just vocab. There’s often a different logic to things and just knowing vocab doesn’t necessarily help you all that much. For example, in English you say “take a bath”, but the Japanese equivalent is “enter a bath” お風呂に入ります(おふろにはいります). Plus you can learn things faster in chunks rather than individual pieces.
I choose to make mnemonics from those radicals i see in kanji.
Example: 失 Fault
Wanikani gives 丿 Slide 夫 Husband
I See in it 矢 arrow 夫 Husband
So i made mnemonic where Im detective in hotel. In three rooms (room counter is しつ and has 失 has same reading) happened similar crime where on wedding night husband has been shot with arrow in head. It’s my job solve whose FAULT it is. Everyone is shouting “it’s your fault” to each others. Hotel manager has provided rooms with pink bows, arrows, apples and champagne. I take him to prison. It is managers fault, he should have seen what could go wrong here.
Wanikani radicals are for the most part arbitrary. The “real” radical for 午 is actually 十 according to jisho.
I put “real” in quotes because the 214 traditional radicals are just as arbitrary as wanikani’s radicals, just older. Radicals are just a tool to try to categorize and memorize kanji based on similar parts, they’re not some integral part of the kanji.
I think the most useful and consistent part about radicals is their readings. You can usually make a good guess about a kanji’s reading, even if you’ve never seen it before, just based off the radicals. Unfortunately wanikani mentions this exactly one time in some random kanji’s description. It becomes obvious once you learn enough kanji though. I know that’s unrelated to your question but I wanted to mention it since it’s hugely helpful for remembering readings.
Oh. Can you give some useful example? Never heard about this and sounds really good.