It is the bias toward the written form of language inherited by student's of English Literature that obscures this fact. Read aloud, Caucer sounds not much unlike modern American English, and even more like that spoken by the fishermen of my Native Newfoundland (will you argue then that I am not a first-generation English speaker?).
When that our Host had heard this sermon,
He (be)gan to speak as lordly as a king,
He said, "What amounteth all this wit?
What should we speak all day of holy writ?
The devil made a Rev. for to preach,
And of a soldier a shipman, or a leach.
Say forth thy tale, and tarry naught the time.
Lo Depeford, and it is half-way prime.
Lo Grenewych, there many a shrew is in'e!
It were all time thy tale to biggin'e."
Fortunately, you see, my spelling has never known restraint by convention....thos te trooth dide sem mar plane ta mee.