A form of the verb (usually the present participle) in which the base is preceded by the prefix a-. See also: elision.
Introduced by Wolfram and Fasold in The Study of Social Dialects in American English (1974)
Examples and Observations:
"Frog went a-courtin' and he did a-ride."
(English folk song "Frog Went A-Courting")
"I'm a-leavin' tomorrow, but i could leave today"
(Bob Dylan, "Song to Woody")
"A-verbing . . . is a holdover from earlier varieties of English, but it is familiar to modern readers from nursery rhymes and folk songs, both old and modern . . .
"Wolfram and Fasold (1974), who studied the use of a-verbing in Appalachian English in West Virginia, say that the prefixed -a emphasizes the duration of an action. 'She's working' means that she's engaged in a relatively short-term task. 'She's a-working' means that the task is of longer duration. . . . Feagin (1979) [found that] a-verbing was used to intensify the action or to create dramatic vividness. She found that a-verbing forms were common in stories about ghosts, accidents, murders, tornadoes, and other dramatic topics."
(H. Adamson, Language Minority Students in American Schools. Routledge, 2005)
"[In the East Anglian dialect] as in many other dialects, it is usual in continuous aspect forms for participles in -ing . . . to be preceded by a-:
a. I'm a-runnen
b. you're a-runnen
c. he's a-runnen
d. we're a-runnen
e. you're a-runnen
f. they're a-runnen
The history of participles as nominal forms can still be seen from the fact that such transitive verb forms are usually followed by on (which corresponds to Standard English of):
a. He wus a-hitten on it.
'He was hitting it.'
b. I'm a-taken on em.
'I'm taking them.'
c. What are you a-doen on?
'What are you doing?'
(P. Trugdill, "The Dialect of East Anglia," in A Handbook of Varieties of English, ed. B. Kortmann et al. Walter de Gruyter, 2004)
§ 33. (Adverbial･ａ伍xes)
（1） α- Adverbial prefix･ａ- in the adverbs given below is representative of OE. preposition ON. which is shortened to a being closely associated with the following ｗｏｒd.（1）
For thathe's allafiΓe wi' love for her any eye can see, T. D. , VII, 62.
They be coming, sir…･lots of 'em --- a-foot and a-driving,F.M. C. , LIT, 432.
The bullseed William, and took afterhim, hornsａｇｒｏｕｎｄ, T. D.,χVII, 144.
'Tis left opｅｎ ａ-ｐtiTかｏｓｅ,p. B. E. ,χχVII, 308.
Ｃ1，ａｒight, T. D. , VII, 62 ； ａ･hoｒｓｅｂａｃｋ， ibid., LI, 462; ａ-ｓｃｒａｍ，ｖ^.Ｔ.-Ｗ.A., VIII, 99
in. Particip!es ・
§50. (Present participle. ) The present participle takes the prefix ４･ in the ws
I'm a-。ming. sir ;･I’ｍａ-ｃｏｍｉｎｇ, Ｗ.，Iχ, 81. ・
Just now he'sａ-ｓｃａｒｉｎｇ of birds for Farmer Troutham, J. O., I-ii, 9.
1 began to feel quite ａ-ｓinking. ibid.｡，V-vii, 390.
I've COｍｅａ-hoｒｒｏ-ｗｉｎｇ,Mrs. Yeobright, R. N. , III-II, 218. ・，
He's down in the vault theｔｅ, ａ-ｌｏｏｋｉｎｇ ａt the departed coffins, P. B. E. ,χχVII, 307.
l used to go to his house α-ｃ。urting my first wife, F. M. C. , VIII, 67.
This prefix a- is the corrupt form of the ＯＥ.preposition on and the following -ing form was originally ａ verbal substantive.
The ending of the present participle,一ing， has lost the final /g/ in the ws dialect.
-en is often used to represent the loss. ･.
doen ( = doing, W･B., I･iii, 24.)
oilen ( = oiling, U.G.T., ML 14.)
§51.【Past particip】e.) Past participle also takes the prefix a-. This prefix, however,
is not the weak form of OE. on. but the descendant of the older prefixes i-, y from
OE. ge･｡CCf. German ge-} According to Wright (E.M.E.G. 392.), i- and ｙ disappeared
early in the northern dialects, and mostly also in the Midland dialects. But they have
been preserved in many of the modern South Midland and South･Western dialects.
It do make my heart ache to see such pretty open-work as that ａ-biむｒｎｅｄ by the flame･ J･Ｏ･ 3 VI-v,
And there's four ounce pennies, the heaviest ｌ could find, ａ-tied up in bits of linen, for weights,
M. C. ,χVlII, 143.
l was a-forced to go to Lower Mistover to-night,尽,Ｎ･ ， V-VII, 438.
Thus, nothing to sweat about, but since you asked I searched for it...
It´s remainings of good Ole English.