A Corpus-Based Study of Syntactic Complexity in L2 Japanese Writing: Insights from Usage-Based Approaches

Recent research on second language (L2) writing has increasingly emphasized syntactic complexity as a key indicator of L2 writing proficiency. From an emergentist usage-based view, drawing on data from the B-JAS corpus, the study conducted both a longitudinal comparison across proficiency levels and a cross-sectional comparison between advanced learners and native speakers to investigate the features and development trends of syntactic complexity in L2 Japanese writing. Two indices were employed to measure syntactic complexity: the clause ratio (a large-grained index) and the ratio of different types of subordinate clauses (a fine-grained index). The results showed that learners had a higher clause ratio and greater use of te-form clauses at the advanced level than at the intermediate level. However, their use of relative clauses was lower, and their use of te-form clauses was significantly higher than that of native speakers. These findings reveal a syntactic usage tendency among learners, marked by an underuse of relative clauses and an overuse of te-form clauses. From a usage-based perspective, attentional biases from Chinese, frequency-based entrenchment, and the semantic ambiguity of te-form structures may primarily drive the observed syntactic usage patterns.