Cross-linguistic Validation of Processability Theory: The Case of EFL Iranian Students’ Speaking Skill

Abstract This study investigated the validity of processability theory proposed by Pienemann (1998/2015) among Iranian EFL learners’ oral performance. The theory defines six procedural stages for learners in the process of second language acquisition. In order to conduct the study, 10 intermediate EFL learners were selected based on their performance on Oxford Placement Test. Then, they participated in five tasks; namely, interview, spot-the- difference task, picture description, picture identification and story-telling task. Their speech was recorded and then transcribed according to predetermined structures (i.e., interrogatives, word order, and negation) called target structures. The frequency of the occurrence of target structures was calculated based on the emergence criterion. The results showed that Iranian EFL learners produced language structures in the predicted procedural stages as proposed by processability theory. Thus, processability theory can be valid for Iranian EFL learners too.