This study investigates whether second language (L2) learners’ language development and accuracy in production are comparable across oral and written modalities on the basis of Pienemann’s processability theory (PT). Eighty-seven English as a Foreign Language (EFL) learners, from high beginner to advanced levels, completed comparable speaking and writing tasks designed to elicit particular morphosyntactic structures predicted by PT to correspond to L2 stages of development. Time constraints encouraged participants to respond spontaneously, thus drawing on implicit knowledge. Implicational scaling shows correlations that suggest comparable language development between the modalities. However, accuracy was higher earlier in the written than in the oral modality, and accuracy in the written modality was more stable. The results provide a clearer understanding of the similarities and differences of L2 oral and written development and demonstrate that PT can be applied to L2 writing.

本研究根据 Pienemann 的可加工性理论 （PT） 调查了第二语言 （L2） 学习者的语言发展和生产准确性在口头和书面形式之间是否具有可比性。87 名英语作为外语 （EFL） 学习者，从初级到高级水平，完成了类似的口语和写作任务，旨在引出 PT 预测的特定形态句法结构，以对应于 L2 发展阶段。时间限制鼓励参与者自发地回答，从而利用隐含知识。隐含量表显示相关性，表明模态之间的语言发展具有可比性。然而，早期书面形式的准确性高于口语形式，并且书面形式的准确性更稳定。结果提供了对 L2 口语和书面发展的异同的更清晰理解，并表明 PT 可以应用于 L2 写作。