Let me begin my comments on Pienemann's keynote paper by expressing my admiration for the scholar who has developed Processability Theory (PT) over a period of some fifteen years with great determination and perseverance. What in earlier publications (e.g. Pienemann, 1985, 1987) appeared to me to be a rather disparate set of principles aiming to account for a limited set of empirical data (the well known sequence of five word orders of the ZISA study), has now evolved into a coherent theory which meets the demands of falsifiability, as PT's claims are formulated in sufficient detail to allow SLA researchers to put them to empirical test. PT comprises a number of principles of great generality, accounting, in principle, for the acquisition of any structure in any language, thereby exceeding the limits of the ZISA data of natural German L2 acquisition. As such, it is to be hoped that PT will have a healthy influence on the field of SLA research, as this field, in the last few years, has perhaps been dominated too much by the issue of whether L2 learners have access to Universal Grammar.