I’d like to start learning how to write kanji.
For this, I think I’ll have to abandon some simplifications that WaniKani does.
For example, I suspect the left radical in 初 is not actually what we call “spirit” (ネ), because it has an extra line.
Or, I think we sometimes throw together or mix up “wolverine” and “brush”, because the middle horizontal line sometimes passes through the vertical line, and sometimes connects.
Assuming I already know the WaniKani radicals, what would be a good place to learn the differences that are required (or at least very useful) for learning to write kanji?
I’m not sure I agree with the premise that learning the differences explicitly is required to learn to write. I only learned to write a few hundred a couple years ago but I didn’t bother and had no issues. You kinda naturally notice anything you need to notice since youll be yknow… Trying to write it. Why not try just learning to write as is and revisit it this issue once you actually run into problems. Something tells me if you actually look at guides for how to write and not like fonts or anything then this will be a non issue.
Might be a case of overanticipation. It would be one thing if an expert on the topic suggested it to you, but it seems like you have no experience writing and are just assuming this will be a hurdle.
I usually recommend learning the radicals to people who want to take Kanken, because radicals are tested, but otherwise I wouldn’t consider it critical for learning to write.
For writing, it might not matter much whether the “radical” is formally a radical or a Kanji, or what name, but WaniKani’s breakdown is a little too sloppy. wiktionary.org could give a better Kanji breakdown than WaniKani.
Specifically, 礻 with vs without dot, and Winter.
There can more details in writing than just which radicals, as you might have noticed. The last stroke length in Wolverine is one. Some others like the direction of 3rd stroke of 今, and drop direction and shape.
I agree with the others that learning radicals per se is not critical, but actually this is one of the instances where I do think Wanikani does it wrong and you’re better off using the standard names instead of the Wanikani simplification.
The reason being that 衤 in 初 is actually a radical form of 衣 (clothes) while 礻 from 神 for instance is a radical form of 示 (originally an altar, seen in 宗 for instance). Since these are often used as semantic radicals, I think it makes sense to notice the difference, and not just to remember how to write them correctly. Of course 神 would be related to “altar”.
For 初 the link to clothes link is less clear, wiktionary says:
衤(“clothes”) + 刀 (“knife; to cut”) – start making clothes by cutting the cloth.
But you also find this “clothes” radical in other kanji like 袖 (sleeve) and 襟 (collar) where it makes more immediate sense. I think Wanikani obfuscates the meaning of the kanji by calling the radical “spirit” in all cases. I have similar objections to the way 月 is handled, and a small handful of others.
Beyond that if you want to learn to write kanji, then just start writing kanji by following stroke diagrams. Eventually you’ll get the hang of it. There’s no point in studying the radicals as a preliminary step or memorizing their names IMO.
renshuu.org also has options for practicing drawing kanji and the kanji database includes their official radicals. Like others have said, I don’t think there’s a practicality to writing kanji. Unless it helps you memorize them.