Longitudinal L2 Attrition:
A Case Study of a Japanese-English Bilingual Child
Hirai Seiko
Kitasato University, Tokyo, Japan
e-mail: seikio-wh@msb.biglobe.ne.jp
As part of a longitudinal case study of a bilingual child, this paper examines the attrition of the subject's English language proficiency over a period of four years and two months after he moved from an English-speaking to a Japanese-speaking community at the age of 7 years and 2 months. The study investigates how much and how fast language attrition occurs, and at what linguistic levels (phonology, morphology, lexicon and syntax) and in what linguistic skills (receptive skills and/or productive skills) language attrition occurs. The effects of four short trips to the U.S. on the subject's language attrition were also examined. The study further focuses on whether it is possible to prove either of two theories concerning language attrition: cross-linguistic effects and the retrieval failure theory. Data were collected through audio recordings of spontaneous speech, story-recalling tasks and pronunciation tests. The Peabody Picture Vocabulary Test and STEP (Eiken) were used to collect further data.
As a result, the following five points became clear: (1) The subject's L2 attrition began comparatively late, at 10 - 11 months after the change in his linguistic environment. (2) The subject's language attrition was most recognizable in his speaking skills. Attrition in listening skills and productive phonology was less pronounced. Significant change was present in the following three syntactical areas: answering negative questions, omission of sentence subjects and use of the do + NP construction. (3) These three syntactical changes were due in part to simplification or Japanese influence on English. In other words, L1 transfer was observed in his L2 attrition process. Thus, the results of this study support the theory of cross-linguistic effects. (4) The subject in the course of this study regained or relearned some of his English skills during and immediately after trips to the U.S. The findings of this study partially support the retrieval failure theory. Both competence restructuring and performance failure were recognized in specific areas. (5) The findings suggest the subject was also able to acquire new English skills after his language attrition had started. In terms of productive phonology, however, his newly acquired proficiency proved difficult to retain. It is also suggested that increased age plays a role in acquiring vocabulary and pronunciation or correcting grammatical errors using metalinguistic knowledge.
