Is 「やってもた」 the same as 「やってしまった」? What is the grammatical rule behind this?


I have recently seen 「やってもた」 used in a Japanese conversation, I don't remember
the context exactly, but it was something like：

> 久々にやってもた。

After asking my Japanese friend, it turns out to be some kind of Osaka-ben
expression used instead of 「やってしまった」, where the 「も」 stands for 「しまう」. My
friend couldn't give me another use of this so I'm here asking two questions:

  1. Is my explanation of 「やってもた」 accurate?

  2. Can we extract from this example a generic grammatical rule that can be applied to most situation? 

I seek to learn Osaka-ben and I'm trying to replace my old habits, so I would
be very grateful if you can provide some external resources about this or at
least mention your sources.




1) It is "やってもうた" or "やってしもた".  
2) The form "もうた" or "しもた" are shortened forms of "しもうた". The (auxiliary) verb
"しまう" has a stem ending with the glide "w": "simaw-", and underwent different
developments in Kansai and Kantoo regarding inflection. In Kantoo, the "w" was
interpreted as a consonant, and was used to trigger gemination (a.k.a.
[促]{そく}[音]{おん}[便]{びん}) in past tense:

> simaw-ta → simatta

On the other hand, in Kansai, the "w" (back glide) was turned into "u" (high
back vowel), and then underwent further change of vowels (k.a. ウ音便):

> simaw-ta → simauta → simouta

If you are expecting external materials on these sound changes, you may want
to study about ウ音便 and 促音便.




1) It is "やってもうた" or "やってしもた".  
2) The form "もうた" or "しもた" are shortened forms of "しもうた". The (auxiliary) verb
"しまう" has a stem ending with the glide "w": "simaw-", and underwent different
developments in Kansai and Kantoo regarding inflection. In Kantoo, the "w" was
interpreted as a consonant, and was used to trigger gemination (a.k.a.
[促]{そく}[音]{おん}[便]{びん}) in past tense:

> simaw-ta → simatta

On the other hand, in Kansai, the "w" (back glide) was turned into "u" (high
back vowel), and then underwent further change of vowels (k.a. ウ音便):

> simaw-ta → simauta → simouta

If you are expecting external materials on these sound changes, you may want
to study about ウ音便 and 促音便.

