Thinking about 遠慮 and かもしれない has also made me wonder recently whether or not the へん from the Kansai dialect plays a similar role.
For those who don’t know, the Kansai dialect is prevalent in and around Osaka, Kyoto and Kobe. One of the major features of the dialect is changing negative ending from ない to へん like this:
できない → できへん
わからない → わからへん
There’s more detailed information here, but the site makes no mention of why exactly they do this or how it came about. I’m sure there are longer, more extensive reasons it developed that way, but it’s interesting that the dialect has what is essentially a ない-replacer.
Wikipedia has a lot of info on kansai-ben. Go to this url: http://ja.wikipedia.org/wiki/%E9%96%A2%E8%A5%BF%E5%BC%81#.E8.A1.A8.E7.8F.BE and search for: 未然形+「ん」
Hey, thanks for the link. I did browse that page before putting up this post, but I didn’t see anything too crazy. It has a lot of specifics, but nothing theorizing generally (not how by why are they replacing the ない the way they are). Now that I look at that page again, though, it makes me curious about how ず and ぬ might act in the exact same way as all these other ない-replacers. That’s pretty interesting.
I think your anti-nai pogrom is getting out of control… ず and ぬ were used to negate verbs long before anyone thought of using ない that way. They survive in dialects and fossilized corners of 標準語 as a relic of the past, not innovations to avoid ない. I don’t know the origins of へん (I’ll try to look it up!) but I’d be willing to bet that it predates ない in the same way, too.
Yeah, I’m just riffin here. The first clue for へん is the fact that it doesn’t fully replace the distal negative ending (飲みまへん) like かねます does.
So I got home and checked. Makimura Shiyō’s Osakan dictionary confirms the obvious hypothesis that へん is just せん with a consonant change (thus まへん etc. also works), and せん is just せぬ of course. So now we know… the rest of the story.