A corpus-based comparison of syntactic complexity in the speech of native Persian speakers and Persian learners as a foreign language

Abstract Since syntactic complexity serves as a trustworthy indicator, it has been looked into significantly of the language development of native speakers and non-native learners. Accordingly, this study examined 10 syntactic complexity measures in 30 native Persian speakers’ and 28 Persian learners’ monologues, both selected from the Spoken Corpus of Shiraz University in Iran. The results revealed that the mean length of the clause was the shortest production unit, and the mean length of the T-unit was the longest production unit. Similar to previous studies, dependent clauses per T-unit and coordinate phrases per T-unit were used more complexly in both groups. In terms of specific structures, complex nominals per T-unit were used more frequently in spoken Persian. Finally, independent sample t tests were conducted to investigate whether and the extent to which the two groups differed in syntactic complexity measures. The results revealed that clausal length (MLC), subordination (DC/C and DC/T), and sentence integration (T/S) were the four statistically important indicators that distinguish learner proficiency in Persian spoken skill. This research provides teachers and researchers with useful insights into how these four measures can be used effectively as indices of native speech mastery.