The 'uh' sound sometimes before present participles

I’m not sure how it should be spelled, if it even has an official spelling, but i’m going to type it as “a”, since that what it sounds like. It’s mostly done by very rural southerners (ie, country folk). For instance, there’s the old country song by John Anderson where he sings about Little Charlotte and himself “just a swingin’”. I’m simply curious where this evolved from, and how long it’s been going on. I know German adds a ge- prefix before certain verb conjugations (I don’t remember which; I think the past participle) so I figured they or someone else may have an a- prefix that we adopted. Also, does it happen in any English-speaking countries other than the states?

The OED use that seems to fit is that it’s the particle of the verb, used primarily with the past participle but with other parts of the verb, too. It says the construction is related to the German “ge-” usage. First cite seems to be around 1270.

And, oddly enough, that’s how i thought of “ge-” when I had to teach myself just enough German to pass my quals.

The American Heritage Dictionary has a different explanation: The a- verbal prefix heard in highland areas of the U.S. South and Southwest is a contraction of on. Related to noun constructions where it means 1. ‘on, in’: abed - 2. ‘in the act of’: aborning - 3. ‘in the direction of’: astern - 4. ‘in a specified state or condition’: abuzz. About the verbal prefix in dialect, it explains

Honestly, I think your definition is more fitting for what I was thinking than RealityChuck’s. His lists arise and awaken as examples, which aren’t the same as what I’m talking about. I can think of some examples where the “a” would be interchangeable with “on,” although not all, such as the example I listed in the original post. They are nevertheless ongoing processes.

I meant to bold RealityChuck’s name, not italicize it.

I agree; the usage is clearly seen, I think, in the title of the Bob Dylan song The Times they Are A-changin’