A sensitive period for the acquisition of a nonnative phonological system
Immigrants who had learned English at various ages and who had been in the United States for various amounts of time were judged for degree of accent in English. It was found that age at arrival was a strong predictor of degree of accent, while length of stay had very little effect. Other practice and motivational factors were related to accent only by virtue of their correlation with age at arrival. It was suggested that a sensitive period exists for the acquisition of a nonnative phonological system.