Finding variation: assessing the development of syntactic complexity in ESL Speech

This paper examines the development and variation of syntactic complexity in the speech of 66 L2 learners over three academic semesters in an intensive English program. This investigation tracked development using hierarchical linear modeling with three commonly‐used, recommended measures of productive complexity (i.e., length of AS‐unit, clause length, subordination) and three exploratory measures of structural complexity (i.e., syntactic variety, weighted complexity scores, frequency of nonfinite clauses) to capture different aspects of syntactic complexity. All measures showed growth over time, suggesting that learners are not forced to prioritize certain aspects of the construct at the expense of others (i.e., no trade‐off effects) across development. The unexplained significant variation found in these data differed among the measures reinforcing notions of multidimensionality of linguistic complexity.