American English has taken 400 odd years to develop as the result of many influences. Some derived from how English was spoken at the time of the first immigrants and became fixed due to the slow speed of transport and communication across the Atlantic. Some comes from other nationalities, like the pronunciation of "'erb" following the French, or words like "coral" from Spanish.
To develop a such a major change in another language would require several generations of time plus massive forces of colonization, for instance, the way French has changed in Montreal.
For an example of how American was spoken at the time of first settlement, read The Sot-Weed Factor by John Barth. It's a realistic portrait of the time with meticulously researched detail, mesmerizing, intellectually brilliant, covers deep issues and is very funny.
This post was edited by Benedict Arnold at June 6, 2018 4:49 AM MDT
Malizz 