摘要:This is a study with descriptive hypothesis-testing design investigating the true nature of L2 grammatical proficiency by focusing on its component parts. It examines the performance of 60 female EFL learners between 19 and 30 years of age at 2 levels of proficiency using 2 types of computerized Grammaticality Judgement tasks in different orders (i.e. Written Stimulus GJ task and Oral Stimulus GJ task) for each participant at a 1 week interval for 2 weeks per each task to determine the extent to which L2 learners' performance is affected by a few components of grammatical proficiency chosen and manipulated out of a great many that exist (i.e. written-oral dichotomy [viz. modality]) as well as language proficiency while focusing on Subjacency. Participants rendered GJ tasks on a 2-point interval. Results from analyzing the elicited measurement data indicated that the performance scores of the two proficiency groups in the two Grammaticality Judgement tasks did not differ significantly.