Structure-building: variation and the dynamics of language development

Thus far we have seen that sign bilingual learners set out with elementary structural domains in their acquisition of L2 German grammar and that they creatively use the available linguistic means in their production of written narratives. We now turn to the potential development of the early “small” L2 grammars. What do the data reveal in this respect? Is there evidence of structure-building, in the sense of an expansion of elementary structures by an additional functional layer?

In our detailed discussion of the data we remarked on the emergence of several phenomena that are commonly linked to a functional structural layer above the VP, that is, the IP. At the same time, we also noted that learner productions are characterised by variation. The alternate production of target-like and target-deviant structures can be taken as an indication that the expanded structure is not fully exploited “overnight”. What we could see is that (a) verb raising may not apply across the board, (b) there is substantial variation in the area of verb inflection, and (c) learners use a diversity of sentential patterns, including DGS-like formats that do not conform to the target.

Certainly, the variation observed raises a number of questions concerning the nature of language development in this particular acquisition situation. For example, we may ask, why is the expanded structure not fully exploited once it becomes available? What can we glean from the variation observed about the underlying language learning mechanisms? Ultimately, we might address the fundamental interrogation of whether the acquisition of German in sign bilingual deaf learners differs qualitatively from the development of German in other acquisition situations. Before we turn to the endeavour of trying to answer these questions we must acknowledge that our study is only a small case study and that the questions we have raised are complex and deserve further examination in future studies. At the same time, as will become apparent in the following discussion, some important conclusions can be drawn on the basis of the present data that will take us a step further in our aim.

In our discussion we will focus first on what we consider to be fundamental signposts of a structural position outside the VP, namely, auxiliary and modal verbs. Subsequently, as the availability of two verb positions raises the question of the relation established between both, we will look at the evidence for verb raising and the finiteness distinction before we turn to subject-verb agreement and its morphological realisation in the form of verb inflection.