Grammatical Development in Second Languages: Exploring the Boundaries of Processability Theory

ProcessabilityTheory (PT from now on) is a psycholinguistic theory of second language acquisition (SLA from now on), first formulated in a book-length publication by Manfred Pienemann in 1998. Since then, PT has earned a place in many SLA introductions, handbooks, companions and encyclopedias such as Doughty & Long (2003), Gass & Mackey (2012), Kroll & de Groot (2005), Macaro (2013), Ortega (2009) and Robinson (2012). It is one of nine theories of SLA singled out and discussed by VanPatten & Williams (2007), along with four others sharing a cognitive processing approach. Like other theories, PT has its strengths and weakenesses, and does not deal with all the phenomena and processes constraining SLA or contributing to it. However, few theories seem to accommodate such a variety of phenomena or offer the basis for so many new developments. What PT offers is a principled transitional paradigm that deals specifically with grammatical development, and accounts for it. It also contributes an explicit and universal definition of developmental stages, which may be applied in principle to any language-specific developmental trajectory, and which in turn offers a stable point of reference for investigating typologically diverse L1-L2 constellations, learning modalities, environments and populations. From a practical point of view, PT can help in assessing language development in individual learners as well as in constructing a syllabus appropriate for their stage of development. In terms of new directions, as Jordan (2004: 227) remarked, PT “can be seen as ‘progressive’ […] extending its domain, refining its concepts, making the variables more operational, attracting more research.