double modals

[P2052 at AOL.COM]

I've often heard expressions, such as "I may could get that done, "I might
can do it" or "He might could/would do it," which I interpret to mean, "There
is a possibility that the subject will (be able to do) something, but (s)he
won't know until (s)he makes the attempt/effort."  Thus, the sense of both
"might" and "could/would/can" is the epistemic, or logically probable, one
(might=probably; would=will ; could/can=have the ability to).  Compare these
to expressions which indicate a higher probability of an action's being
fulfilled or realized, such as the following:  "I could get that done,"  "I
can do it," and "I know he could/would [not past habitual]/will do it."
                            PAT