I was on Reddit recently and realized that Edogawa is basically just Edo river directly translated. Then started to think about it more and wondered what decides when the dakuten gets added like in the example I gave. Any help would be appreciated
Doesn’t seem to be any real good rules for this, nothing reliable anyway.
Despite the lack of rules, you can get used to it and be able to reasonably reliably guess when to use a rendaku. Mostly comes down to the way a word feels, if it is easier to say or flows better with a rendaku, then it probably has one.
I think you’re referring to rendaku?
There’s a nice article on Tofugu: https://www.tofugu.com/japanese/rendaku/ with the rules, etc.
But as a beginner, its best to just “go with the flow”. Notice words with rendaku and try to “get a feel” of when it’s used, while not thinking about it too much.
Didn’t realize that there was a special name for it. Thank you
If you’re on desktop there’s a great userscript that adds rendaku rules for that word in Lesson and Review format.