Alignment of code switching varies with proficiency in second language learning dialogue

Speakers in dialogue tend to adopt the language patterns of the other, aligning their language to their interlocutor. This can happen at many levels of communication, including the tendency to code switch (CS), or change to another language. Alignment has often been considered the result of an unconscious automatic process that facilitates speakers' mutual understanding. In dialogues with a second language (L2) learner, alignment is constrained by the proficiency of the learner, and additional non-automatic processes will be at play, namely the individual pedagogical goals of learner and tutor. In this study, we investigate alignment in dialogues between Spanish/ Catalan learners of English and their tutors. We analyse CS incidence, whether code switching can be explained as automatic alignment between speakers, and whether this is independent of other, non-automatic factors related to speakers' goals. We find that alignment of code switching is present, varies with learner proficiency, and that code switching can additionally be triggered by lexical overlap and turn taking asymmetry, which we attribute to conscious pedagogical choices on the part of both tutor, at lower levels, and learner, at higher levels of student proficiency.