Task complexity and grammatical development in English as a second language

This study investigates whether second language learners’ interlanguage system changes according to the tasks one performs. This has important implications concerning the validity of language testing and assessment. In particular, this study tests Pinemann’s (1998) Steadiness Hypothesis within Processability Theory (PT), which states that the basic nature of the interlanguage system does not change across different communicative tasks provided they are testing the same skill type. Our informants are 30 Chinese L1 learners who are learning English as a second language (L2), 10 for each of the three IELTS bands: Low-Intermediate (IELTS 4.5-5.0), Intermediate (IELTS 5.5-6.5) and High (IELTS 7.0 or above). The informants performed two oral production tasks involving different cognitive complexities, which manipulated the variable of +/- planning time based on Robinson’s (2011) Cognitive Hypothesis. Analyses revealed that the within-learner competence measured by Pienemann’s L2 developmental stages was quite stable in terms of syntactic complexity regardless of the cognitive complexity of the task. On the other hand, L2 learners’ performances, measured by rule applications and grammatical accuracy, varied especially with lower level learners. Thus the study investigates whether L2 competence as defined by PT varies according to task complexity variables as defined by Cognitive Hypothesis. The results bridge a gap between two unrelated theories.