L2 fossilization: a competence or a performance phenomenon

The study reported here examined the question whether fossilization occurs as a result of competence deficiencies or is a function of processing constraints, i.e., a feature of performance. To address this issue, we first collected longitudinal data (2 years apart) from an adult second language (L2) learner of English. Error analysis conducted on our subject’s L2 output revealed features that are consistent with the occurrence of fossilization: steady below norm levels of grammatical accuracy, fluctuation between correct and incorrect usage of the same structure, and backsliding. Next we used a grammaticality judgement (GJ) task to examine our subject’s intuitions about the English article – the most pervasive error in his output; we also administered the same GJ task to eight native speaker controls. The analysis of the data from the grammaticality judgement task showed a clear mismatch between our subject’s intuitions about article usage and those of the controls, suggesting that fossilization is most likely a competence phenomenon.