Rosetta Stone offers two dialects of English for learners, English (British) and English (American).
spoken, with considerable regional variation, throughout the United Kingdom.
common, with considerable regional variation, in countries that were once part of the British Empire (such as South Africa, New Zealand, Australia and the British Isles)
spoken throughout the United States
widely understood by English speakers in other parts of the world. Most Canadians speak a combination of both English (American) and English (British).
The differences between the two versions appear in pronunciation, spelling and vocabulary. The vocabulary differences occur
as false homonyms (the same word having separate meanings)
as synonyms (the same object or concept having different words in the two languages).
Rosetta Stone teaches you to distinguish between these words through context.