Nigerian English, Indian English and American English all sound very different from British English — and each other — even though all were influenced by English colonizers. So, how does this happen? Let's look at the phenomenon as it applies to American English.
Surprisingly, "when the British colonized America, they sounded similar to Americans today," says Canino. "The English spoken by both the British and the Americans was rhotic, meaning the letter "r" was pronounced. "This all changed around the American Revolution when wealthy people in southern England wanted a way to distinguish themselves from the lower classes. That's when British English became, for the most part, non-rhotic. Over time, this 'highbrow' manner of speaking became standardized."
Of course, there are several types of American and British accents depending on which part of the country the person lives, and, particularly in the case of Britain, what social or economic class he or she may come from. But that "r" distinction is one that is obvious. "Americans are heavy on the "r" sound while Brits use the schwa sound all the time (think of the last sounds in words such as butter or better)," says Katja Wilde, head of didactics at language-learning app Babbel, via email. "Also, the British accent is widely known for its pronunciation of 't' in words such as 'water' or 'later'. While [some] Brits put a glottal stop (water becomes war'er) Americans usually have a soft sound closer to a "d" than a "t" (water becomes wa-dder)."
Another reason for the differences in accents between Americans and Brits is the influence of immigrants on the U.S. "Certain regions of Boston are heavily influenced by the Irish immigrants who settled there, and others more so by their Italian heritage. Traits of the accent or even the language spoken by the settlers often leave traces in the language, including pronunciation, word choice and overall melody of one's speech, " says Canino.
But then we have the phenomenon of British singers — as varied as Adele, George Michael and Tom Jones — sounding like Americans when they belt out tunes. "The reasons for this are debated by experts, with some saying that the shift in accent when singing is due to the success and popularity of American pop singers, with a lot of genres actually originating in the United States," says Wilde. "Others argue that singing in an American accent is a stylistic choice — with so many influencers in the music industry coming from the States, it is simply easier to sing lyrics in the American accent to follow the music."
Canino has an interesting theory on the phenomenon. "Each accent has a unique set of characteristics such as tone, inflection and rhythm. When we sing, we follow a melody which often cancels out these unique characteristics. That's why many singers sound like they have a very neutral standard American accent," he says.
There are exceptions, of course, like the Scottish band The Proclaimers, who sing in thick Scottish accents or the band Oasis, which hails from Manchester, England. "[They] would never be mistaken for Americans, but they probably make an effort to sound British when they sing," Canino adds.