The process and rate of acquisition by second language (L2) and bilingual first language (L1) child learners: A case study of Japanese morphology.

This longitudinal study analyzes the acquisition of some aspects of Japanese morphology by two children within the framework of Processability Theory (PT) (Pienemann, 1998a). Both children were acquiring Japanese in an English-Japanese bilingual context, but one was acquiring Japanese as a second language (L2) and the other as a first language (L1) at the time of the study. The study focuses particularly on the process and rate of acquisition by the two children and examines whether they acquired selected Japanese morphological structures in a similar manner. The results show that both the L2 child and the bilingual L1 child took a similar route in the process of acquiring morphology in Japanese. However, the acquisition rate of the L2 child was faster than that of the bilingual L1 child. This may be attributed to the different levels of generic cognitive development and the developmental stage of the other language on which the two children of different ages built their acquisition of Japanese.