The Elf Herself writes:
There are regional language differences (and certainly pronunciations!) in American. While we aren't the largest country in the world, by any means, the distance between New York and Los Angeles, for example, is about the same distance as London to Moscow, or Rome to the Gulf of Aden. People on our east coast tend to drop the final "R" ("pow-ah" instead of "pow-er," for instance) because most of the old-timers in the south and east had their roots in England, Scotland and Wales, while the late-comers in the west were gold-hunters lured by California's Gold Rush, former Spanish and Mexican colonists who stayed on after a lot of the western territories became part of the U. S., and penniless Southern veterans on the losing side of our terrible Civil War of the 1860's. As such, the U. S. has some regional grammatical constructions that sound weird to those from other parts of the country. For example, the plural form of "you": east: "youse," midwest: "you-uns," south: "you all," further south and parts of southwest: "y'all."
A lot of Texans put "tars" on the car, and apply "tire" to their roads. In Oklahoma (right above Texas) when I was unable to figure out the lock on the door to the toilets, I was told to "kindly mash down on the button." And when setting the table for dinner, and I forget something, I'll usually exclaim, "Oh, wait! I'll get you a fork." (Never "I'll get a fork for you.")
Texans also add another syllable to most single syllable words. "Hell" is always "Hay-ull," and the common expletive for defecation is always "shee-it!"
When I was in Pennsylvania some years ago, someone asked me if I wanted to go get a "frozen custard." I was baffled--was there really a dessert or snack consisting of taking the trouble to bake a custard, then freeze it? Turns out that was east coast-ese for soft ice cream (called "frosties" in California.) Sandwiches served on long buns are heroes, submarines, po' boys (southern for "poor boys," and I forget the ones starting with "B." Bones probably knows.)
So America is a country separated by several English-sounding languages! (Peter2, I think the U. K. is, too. I don't think a Liverpudlian, a Geordie, a Welshman, and a Northern Irishman would be able to converse much beyond, "Anyone want a pint?" [And if a pint is to be had, I'll be right there!])