Syntactic complexity of interpreted, L2 and L1 speech: A constrained language perspective

This study investigates the differences in syntactic complexity among three language varieties: interpreted speech, nonnative English (L2) speech, and native English (L1) speech. The examination was conducted through the evaluation of 14 measures across five subconstructs: the length of the production unit, the amount of subordination, the amount of coordination, phrasal sophistication, and overall sentence complexity. We used a self-compiled comparable corpus of these three language varieties and tested the simplification hypothesis under the framework of constrained language. Our results showed that the two spoken constrained varieties, interpreted speech and L2 speech, had significantly lower scores on most of the syntactic complexity measures compared to non-constrained L1 speech. However, there was no consistent pattern between the two constrained varieties. Specifically, interpreted speech had longer language units and more coordination than L2 speech, which contained more subordination. Overall, this study provides new insights for simplification research by examining syntactic complexity measures from a constrained language perspective.