It remains to be a puzzling question why some people are more successful in learning a second language (L2) than others and under which conditions. In my dissertation I studied the effects of several factors, including the starting age of learning a L2, the amount of continued exposure to the first language, and the achieved level of education, on naturalistic second language acquisition.
I looked at 102 oral history testimonies given by German-Jewish immigrants in the U.K., the U.S.A., and Australia who had arrived there when they were between 7 to 17 years old. They all had been forced to leave Germany either by themselves or accompanied by relatives between 11 November 1938 and 1 September 1939. They had given these interviews in their L2 English when they were between 57 and 87 years old. Hence, all of them had spent the majority of their lives in the L2 community in which they had established themselves.

The interviews were particularly analysed for vocabulary and grammar, pronunciation, and fluency.

We found that vocabulary and grammar were significantly related to the interviewees’ level of education. Their pronunciation was significantly related to the interviewees’ age at which they started learning the L2. Fluency was significanlty related to the age at which the interview was given.

Altogether, our findings suggest that second language acquisition is related to a set of factors, including the level of education people obtain and the age at which people start learning a language.