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.

中文翻译：

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口语和书面形式的二语语言发展

本研究根据皮内曼的可加工性理论 (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中是否具有可比性。 87 名英语作为外语 (EFL) 学习者，从初级到高级，完成了类似的口语和写作任务，旨在引出 PT 预测的与 L2 发展阶段相对应的特定形态句法结构。时间限制鼓励参与者自发做出反应，从而利用隐性知识。蕴含尺度显示了相关性，表明两种模式之间的语言发展具有可比性。然而，书面形式的准确性早于口头形式，并且书面形式的准确性更稳定。结果使人们更清楚地了解二语口语和书面发展的异同，并证明 PT 可以应用于二语写作。