The best work on this has been done by Elissa Newport and Sam Supalla who have studied people who have been in the United States for many, many years like 30, 40 years and seeing how well they have come to speak English.

在这方面最佳的研究,是由伊莉萨·纽波特,和萨姆·苏普拉所进行的,他们研究了在美国生活了,三四十年以上的人们,探究了这些人们讲英语的流利程度

心理学导论课程节选 : 耶鲁公开课