I returned to WK several months ago after a long absence and reset my progress. When I re-unlocked 利く, I remembered it as meaning “to be effective.” However, that definition is no longer accepted as correct, and the primary definition is “to work well.” I tried looking up the word in my Japanese dictionary and discovered two things: a different kanji is more typically used for that word (効く), and “to be effective” is a primary definition for the word.
Can anyone share any insight into:
Whether and when to use 利く instead of 効く
Why WK might have removed “to be effective” as an accepted definition of the term (I don’t want to add the user synonym if it’s not truly a synonym)
Like you said, 利くwould be more along the lines of “to work well” - the kanji itself means profit or advantage
効く is more like “to be effective/efficient” - the kanji means effect
Looking at more vocab terms using the kanji can give you some more insight into the nuance of the meaning.
It is similar to cases such as 上る (to rise) 登る (to climb) 昇る (to ascend) or 見る (to look/see) 観る (to watch/view) 看る (to watch over) 診る (to examine) in which the meaning is similar but using certain kanji allows you to be more nuanced.
As for removing the accepted definition, I guess WK wanted to be more specific/accurate with 利く vs 効く
By the way, even native speakers may be tripped up by that kind of things, that’s why you have websites dedicated to the difference in nuance between such words.
For 効く vs 利く: 「効く」と「利く」 - 違いがわかる事典
