[duaneb]

Less of an American accent? Surely their English would be unchanged but for vocabulary; it's not like grammar differs.

Anyway, just because a country is a language's namesake does not indicate anything but history. A language is a dialect with an army, so perhaps we should rename it American. Names of languages are arbitrary.

[stan_rogers]

Grammar does differ, though, in subtle ways that don't necessarily impede communication but that mark the speaker for region. The participle gotten is probably the most prominent example; it is essentially unknown in most British English varieties and tense construction has more irregularities in British English than it tends to have in US English. (We Canadians speak both and neither, and nobody really knows the rules from day to day. They change on a pseudorandom sort of schedule covered by the Security of Information Act, and those in charge will neither tell us what's going on nor reveal their identities.)