The Dynamic Patterns of Syntactic Complexity in Chinese EFL Learners’ Writing Based on a Longitudinal Learner Corpus

This study tracks the development of syntactic complexity in the writing of Chinese EFL leaners over six semesters of collegiate language study by using a longitudinal learner corpus. The focus of the investigation is on the developmental trajectories interpreted from the perspective of Dynamic Systems Theory (DST). The self-compiled corpus (about 100,000 tokens) contains timed compositions of 79 students, through 6 semesters (3 years). This study explores developmental patterns in terms of four indices: clauses per T-unit (C/T), dependent clauses per clause (DC/C), verb phrases per T-unit (VP/T) and complex nominals per T-unit (CN/T). The results show that during the observation period, there exist different developmental stages in syntactic complexity, with fluctuated and linear patterns appearing alternatively. The phasal characteristics indicate the existence of attractor and repellor states. The mean length of T-units form connected growers with VP/T, followed by NP/T, C/T and DC/C, according to their magnitude of significance. This study also addresses one of the controversial issues in syntactic development. It proves that slowing-down or standstill in C/T and DC/C, reinterpreted from the DST perspective, does not mean the non-advance of learners’ syntactic complexity. Complemented by the detailed analyses of VP/T and CN/T, the research verifies the phrasal orientation in development, offering empirical evidence for the hypothesis that learners adopt multiple strategies in syntactic evolution, besides the increase in length. The major findings in this study—phrasal orientation, the stage characteristics, and connected growers—serve as empirical evidence for the explanatory power of DST in explaining second language development. Meanwhile, the result also challenges the validity of C/T and DC/C as sound syntactic development indices, as has been recommended generally by some researchers. Suggestions for future developmental second language acquisition research and foreign language pedagogy are made.