Adding -い at the end of questions

Question

どうしたんだ　vs　どうしたんだい

そうか　vs　そうかい

This kind of thing. Is it a formality difference? Is it dialectical/Regional? Age related?

Related: https://japanese.stackexchange.com/a/15770/9831 / https://japanese.stackexchange.com/a/16116/9831 — chocolate, Oct 02 '19 at 09:48

score 1 · Answer 1 · answered Oct 02 '19 at 19:02

1

The i at the end is a shortened form of yo Sou kai = sou ka yo. Doushita ndai = doushita nda yo.

Its slang.

answered Oct 02 '19 at 19:02

skekTek

3

Interesting theory; do you have any source on that? – Igor Skochinsky Oct 02 '19 at 19:05
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https://www.sljfaq.org/afaq/kai-question-particle.html. in Wikipedia tho, kai is its own particle. But the link suggests its origin came from the ka-yo particles – skekTek Oct 02 '19 at 19:15
That theory doesn't have consensus, and apart from etymology, it's not interchangeable to current "yo". – user4092 Oct 02 '19 at 22:57
Yeah, this answer seems to imply that hey can be used interchangeably. – Leebo Oct 03 '19 at 00:10

1 Answers1