The annotation of learner language is an often ambiguous and challenging task. It is therefore surprising that in Second Language Acquisition research, information on annotation quality is hardly ever published. This is also true for verb placement, a linguistic feature that has re- ceived much attention within SLA. This paper presents an annotation on verb placement in German learner texts at different proficiency levels. We argue that as part of the annotation process target hypotheses should be provided as ancillary annotations that make explicit each annotator’s interpretation of a learner sentence. Our study demonstrates that verb placement can be annotated with high agreement between multiple annotators, for texts at all proficiency levels and across sentences of varying complex- ity. We release our corpus with annotations by four annotators on more than 600 finite clauses sampled across 5 CEFR levels.

Developmental stages are a linguistic concept claiming that language learning, despite its large inter-individual variance, generally progresses in an ordered, step-like manner. At the core of research has been the acquisition of verb placement by learners, as conceptualized within Processability Theory (Pienemann, 1989). The computational implementation of a system detecting developmental stages is a prerequisite for an automated analysis of L2 language development. However, such an implementation faces two main challenges. The first is the lack of a fully fleshed out, coherent linguistic specification of the stages. The second concerns the translation of the linguistic specification into computational procedures that can extract clauses from learner-produced text and assign them to a developmental stage based on verb placement. Our contribution provides the necessary linguistic specification of the stages as well as detaiiled discussion and recommendations regarding computational implementation.