English Proficiency Score and Age of Arrival in U.S.

Sensitive period for second language acquisition. English language proficiency scores as a function of age of arrival in the United States for a group of Chinese and Korean adult immigrants (n = 46). All subjects were students or faculty at the University of Illinois and had been in the United States for at least 10 years before testing. The test measured a variety of grammatic judgments. Data are from Johnson and Newport (43).