The development of morphological complexity: A cross-linguistic study of L2 French and English.

Studies in second language acquisition (SLA) increasingly rely on measures of linguistic complexity
to assess second language (L2) proficiency and development. While an important number of studies
have risen to the call of studying a broader range of complexity related constructs (Bulté and
Housen, 2012; Norris and Ortega, 2009), few have examined morphological complexity, instead
focusing on syntax and lexis. The use of morphology measures is especially warranted in light of
complexity trade-offs believed to occur both in language development – when growth in one linguistic
domain (e.g. syntax) is temporarily prioritized over growth in another (e.g. morphology) – as well
as crosslinguistically, in the form of balancing effects between different domains of the linguistic
system. From both a cross-linguistic and developmental perspective, then, the current emphasis
in SLA research on measures of syntactic complexity does not comprehensively gauge overall
(grammatical) complexity in learner data. This study focuses on the development of morphological
complexity using three previously proposed measures based on the notion of morphological
diversity, with special attention to the verbal inflectional system (Horst and Collins, 2006; Malvern
et al., 2004; Pallotti, 2015). Not only does the verbal system pose significant challenges to language
learners, it is also the locus of important differences between inflectionally richer languages, like
French, and inflectionally poorer languages, like English. The study investigates cross-linguistic
differences in the development of morphological complexity and the effectiveness of the three
morphological complexity measures as indicators of proficiency. The analyses were carried out on a
multilingual corpus of 100 L2 French and 100 L2 English oral narratives, representing four different
proficiency levels in both languages. Results indicate a more continuous increase of morphological
complexity in L2 French than in L2 English and underline the importance of morphology as an
essential component of a multidimensional view of linguistic complexity in SLA.

Keywords:Second Language Acquisition, Complexity, Linguistics, Morphology, English, French