Some kanji I’ve seen end up having the same meanings, like 芽 and 萌 as an example. Which “sprout” is correct? Can they be used interchangeably or is one kanji more common? I know this isn’t the only case of same-meanings, so what do you usually go with when it comes to these words?
Usually kanji with the same meaning can cover different nuances or be used in different cases. Don’t know about these two in specific though
Kanji in general are not in and of themselves words. Some kanji are also words, but the abstract idea of “the kanji” and “the word” are still separate ideas.
In this case specifically, 芽 as a stand-alone word is as you said, “sprout”, like a budding plant.
On the other hand, 萌 is not a word by itself. Additionally, 萌える would be the verb “to sprout” as opposed to “a sprout”.
Sidenote: 萌 is also used in some slangy ways regarding crushes on anime characters.
Usually it’s just that the English words aren’t fine-grained enough. Using a monolingual dictionary can get you more info.
to be fair, there are quite large thesaurus for english, so it’s not like we don’t also have similar problems lol it’s just more noticeable to japanese learners as its new and in a very different form that many will have been used to.
More examples from Wanikani:
生まれる and 産まれる. Same meaning, same pronunciation, different kanji.
交ぜる and 混ぜる. Same meaning, same pronunciation, different kanji.
In these cases, I don’t know if there’s any minor connotations or not. If there is, it’d be nice if WK would show it just for curiosity.
When I was an exchange student in the U.S., I drove my host family crazy by constantly asking “What’s the difference between (synonyme1) and (synonyme2)”. Eventually, they gave me a thesaurus for my birthday.
What I’m trying to say:
I think connotations can wait until you’re moderately fluent and can read Jp-Jp dictionaries.
Wanikani helps you “put a pin into a word”, as Cure Dolly would say, so that when finding it in the wild, you’ll get the essence of the text you read. It’s not for teaching you when to use what word when speaking/writing yourself. That is way too fine grained for a Kanji teaching app (and for most people on the respective level).
WK gives you the tools to read those words and understand the basic meaning when you see them. Yes, they have more nuance than the basic glosses give you, but if you’re interested you can always search something like 生まれる 産まれる 違い.