a-dancing and a-singing

[Suzanne Kemmer]

Brian, further comments:

1.  "Dad, I'm on it!"
Very different construction--does not mean 'be in process of doing  
something' (except by inference),
but rather 'have something taken care of, have accomplishment of a  
desired/needed action in view".
The metaphor is the idea of being on top of something in the sense of  
'be in control of what needs to be done and ready to do it/have it  
done."
Recently subordinates have emphasized their eagerness with
  "I'm all over it" , cf. conceptually similar  "I'm on top of it" and  
"I've got it covered".
I agree with Steve Long that "I'm on it" is  a widespread military  
expression and may have spread into business and other domains from  
there.
    (Steve Long wrote:   "As to “Dad, I’m on it.” -- it's military in  
my experience and short-form  for "on top of it" or "on that detail." ")


2. Re: the so-called "absentive":
I think the sense of 'absence' is restricted to a more complex and  
specific variant
of the plain vanilla progressive  with aux _be_  (_be V-ing_/ _be a-V- 
ing_), namely b. below.

a. In 1st special case, progressive _-ing_ verb form combines with  
_go_ instead of _be_,
and V is (I think always) an intransitive action verb:
_to go a-V-ing_
e.g. "a-hunting we will go"

V without prefix is now the standard variant:
_go  V-ing_   "go swimming"  (productive with all tenses,  incl. with  
progressive, e.g. I went swimming,  I am going swimming, etc. ).

b. The second, "absentive" construction extension is one form of a.  
above,
  specifically with past participle form of _go_ (which historically  
always took auxiliary _be_ instead of _have_).
Here's where the extra-specific sense of "absence" comes in:
_to be gone a-V-ing_
e.g. "Daddy's gone a-hunting"  (from song "Bye-bye baby bunting")

I've haven't read de Groot article so don't know how the quasi- 
auxiliary _go_  is taken into account in his history  of _a-V-ing_ .
But I don't think  _a-V-ing_   by itself has any "absentive" sense  
without that past part.  form of _go_,  at least in present day English.
The "absence" idea  seems to be mainly due to the _go_; the  
construction also occurs without the prefix  as in "He's gone fishing".
That's why I wouldn't connect the 'absentive' meaning with the  _a- _
prefix specifically, but perhaps de Groot's historical account deals  
with this.

c. _ a-V-ing_  can also be combined with the futurative _be going to_   
construction --
here, _go_ fits in the V slot after _a-_, and then we get another,  
complement inf. V:
  _be a-going to V / be a-gonna V _   (the Dylan "a hard rain's a- 
gonna fall" example  fits here).

_Going to /gonna V_ was originally progressive in sense,  but in the  
futurative gonna construction
the present is backgrounded in favor of (orig.  immediate) future  
meaning.
The idea of immediacy of planned action is what diachronically links  
presents /progressives with futures more generally in languages,
  as speakers use present to indicate what they're about to do (as  
also in  "I'm on it" above) and gradually use it only to SUGGEST  
soonness
even if they aren't immediately intending to act.  Eventually '  
soonness'  can fade entirely and leave general future.

3. Finally, a note on tagging:
The a- is a prefix in mod. English,  and treating it as a preposition  
might give other problems.
That progressive -ing form is not a noun anymore.
We would want to search those forms as verbs, and the prefixed and non- 
prefixed forms should be
parallel.

Suzanne