Syntactic complexity in L2 writing: Progress and expansion

In this commentary to the Special Issue, I first identify four themes that arise from the contributions that each study makes to the study of syntactic complexity in L2 writing. I then explore several other themes that stem from the collective findings from the five studies and which connect with the general landscape of the research domain. Two questions guide the domain. One question is substantive: What do we know about how syntactic complexity grows, and what factors affect this growth? The other question is methodological: How can one best measure syntactic complexity? Both, of course, are interrelated. An overarching conclusion is that much progress has been made in what is already known, substantively and methodologically. An emerging insight is that we can look forward to several areas of expansion that are imminent in the domain. (C) 2015 Elsevier Inc. All rights reserved.