The UG paradox in L2 acquisition

There is a considerable amount of recent evidence that stable principles of Universal Grammar (UG) are available to adult second language (L2) learners in structuring their intuitions about the target language grammar. In contrast, however, there is also evidence from the acquisition of word order, agreement and negation in German that there are substantial differences between first language (L1) and L2 learners. In our view, these differences are due to UG principles guiding L1, but not L2 acquisition. We will show that alternative ways of accounting for the L1/L2 differences are not successful. Finally we will deal with the question of how our view can be reconciled with the idea that L2 learners can use UG principles to some extent in the evaluation of target sentences.