Lexico-syntactic complexity and accuracy in heritage language learners at different proficiency levels: a cross-sectional study

Research on second language (L2) learning using complexity measures has identified key developmental parameters with practical implications for language instruction and related fields. These parameters, however, might not necessarily apply to heritage language learners whose linguistic profile is different from that of L2 learners. This study addresses that gap by analyzing several complexity measures in Spanish heritage language samples. These measures include accuracy, and lexical and syntactic complexity in written texts produced by Spanish heritage language learners enrolled in college-level heritage language courses in the United States. The samples represent writers at four different ACTFL-based functional proficiency levels: Intermediate Mid, Intermediate High, Advanced Low, and Advanced Mid. The results showed a linear increment in accuracy as proficiency increases. Additionally, the study found changes in lexical and syntactic domains at the transition between Intermediate sublevels, whereas Advanced learners demonstrated greater sensitivity to changes in lexical measures. Taken together, the findings indicate that accuracy and text length are the strongest correlates of ACTFL-based functional proficiency sub-level in this group of HLLs.