As I'm encountering more words with rendaku, I thought I started to understand it, but I came across an example that does not make sense to me.

Why is 気 voiced き in 元気 and 本気, but is voiced ぎ in 一本気 ? In other words, why is there no rendaku in 本気 ?

From other questions, I see that there is some unpredictability about rendaku… but those words are really close to one another.

  • 4
    Not entirely sure, but I suspect part of why you're seeing a difference there is that 一本気【いっぽんぎ】 is 一本【いっぽん】 + suffix 気【き】, and suffixes tend to be more susceptible to rendaku. Meanwhile, 本気【ほんき】 is 本【ほん】 + 気【き】 where 気 is the head or main noun, and 本 is used here semantically (meaning-wise) as an adjective modifying that noun -- I think we don't see rendaku here because 気 is the head noun. Feb 2, 2021 at 17:11

1 Answer 1


Rendaku occurs when two independent words come together to form a compound. I think 一本気 is a compound, while 本気 and 元気 are not. (Just because they are analyzable as 本+気 and 元+気 doesn't mean they are compounds. 元 and 本 are not independent words, unless you mean "a book" by 本.) Also, Sino-Japanese words don't normally participate in rendaku. In that sense, 一本気 is exceptional.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .