Abstract：Abstract: The learning effects of XU have been extensively validated by quantitative studies, with significantly less amount of qualitative research probing into the process in which XU facilitates language learning. This study reported on a case study investigating how two XU variables, i.e. alignment and attention focus, influenced the acquisition of the English regular past tense –ed. Subjects were two L2 learners of English with one benefiting more from interpersonal interaction and the other benefiting less in a listening-to-speak task. An analysis of their interaction language episodes yielded the following results: 1) efficiency of acquiring the –ed form depended largely on the contingency of nonlinguistic alignment upon linguistic alignment; 2) the faster acquirer tended to extend the use of the linguistic target creatively on the basis of imitation whereas the slower one would not; 3) the faster acquirer paid attention to both meaning and form while the slower one to meaning and key words; 4) these differences in alignment and attention focus were closely associated with learners’agency. In short, the degree to which alignment and attention focus were activated hinged on learners’agency to use the L2.
Key words: XU; nonlinguistic alignment; linguistic alignment; attention focus; agency
