Interference as a developmental indicator in early German after English: a classroom-based study with Chinese learners

Research on Third Language Acquisition (TLA) has underscored the pivotal role of previously acquired languages in shaping the trajectory of L3 development. Nevertheless, non-target-like structures in early L3 learning are frequently dismissed as mere errors. This classroom-based study examines how such phenomena can be understood from a developmental perspective in the context of German learned after English by Chinese university students. Using a quasi-experimental design, the study compares a group receiving explicit support in cross-linguistic strategy use with a Control Group. Quantitative vocabulary measures and qualitative analyses of lexical association tasks were employed to explore differences in lexical organisation, cross-linguistic activation, and the occurrence of non-target-like forms. The findings suggest that learners who actively draw on prior linguistic knowledge tend to develop more extensive and interconnected lexical networks, while also temporarily producing more interference forms. Many of these forms appear to decrease over time as the developing language system stabilises. Interference and successful transfer may therefore be understood as parallel outcomes of multilingual processing rather than as opposing phenomena. From a pedagogical perspective, the results support integrating learners’ existing linguistic repertoire and interpreting interference as a developmental resource rather than solely as error.