"Gwine"

[Paul Johnston]

"Gwine" (or phonemically spelled "gwain", but pronunced [gwaIn] in many
dialects) is common in the Ellis (1889) and Survey of English Dialects
(1962-69) data, with a Southwestern English distribution.  Not only did many
English Southwesterners come to settle in the American South (esp. South
Carolina and the Caribbean), but a lot of slave ships operated out of
Southwestern-speaking ports (Bristol, Southampton, Portsmouth, Plymouth).
Either way--and whether you buy the Anglicist or Creolist hypotheses for the
genesis of AAVE, and "gwine" is usual in Gullah and Caribbean Creoles (if
not in African ones)--it could have been part of the English lexifier
dialect of Creoles, AND a part of early (White) Settler English quite
easily.
Same with the merger of LOIN/LINE under the latter, which is not only well
attested in 17c/18c Standard varieties, but is found in a wide variety of
English dialects, including some Southwestern ones (and Scots also).  In
fact, quite a few AAVE and Southern features are found in SW English
generally--and this is coming from someone who mostly buys the Creolist
hypothesis, so I tend to see SW English as a lexifier/donor dialect, later
reinforcing these features on these shores.

Yours,
Paul Johnston
Western Michigan University