Szrow zee ball!
There are scientific reasons why many immigrants can’t get the sz out of “throw” or the z out of “the.”
Most likely, those who speak with an accent emigrated after the age of 8. Since the critical period for language development begins in infancy and ends between eight years and puberty, it’s difficult to speak a second language without an accent after that time.
“Second languages learned after the critical period are not processed in the same part of the brain as is the native tongue,” writes Dr. Norman Doidge in The Brain That Changes Itself.
Language development may even begin in the womb. By comparing the cries of French and German newborns, researchers have found that French newborns cried with a rising “accent” while German babies’ cries had a falling inflection. The researchers concluded that by mimicking their mothers’ intonations, the babies are attempting to bond with their mothers.
Since the brain is plastic, non-native speakers can learn to speak a second language without an accent, but it requires intense training. Dr. Michael Merzenich, professor emeritus at the University of California at San Francisco and a leading pioneer in brain plasticity research, has helped Japanese people learn to speak accent-less English by grossly exaggerating the r and l sounds so that they could pick up the difference.
But do we really want to do that? Clearly, accents reveal our origins, who we are, and where we are going. They tell our life stories.