本研究根據時貌假設理論探索詞彙時貌對台灣中學生英語過去式習得之影響。 總計113位九年級生參與並探討以下主題：（1)時貌假設針對過去式之預測；（2)第一 語言對於過去式使用之影響，及(3)學習者二語精熟程度與各詞彙時貌過去式使用之 關係。統計數據支持時貌假設之預測。即，過去式先與終結動詞聯結，再擴散至活 動動詞，最後展延到狀態動詞。本研究也發現中文完成貌標記「了」對英語過去式 可能具有正面遷移效果。此外，當英語精熟程度提升時，時貌假設對學習者過去式 使用之影響將會減弱。最後針對未來研究方向及英語教學提出建議與啟示。

The study aims to investigate the effect of lexical aspect on L2 acquisition of English past tense by basic-level EFL learners in Taiwan in terms of the Aspect Hypothesis proposed by Andersen and Shirai (1994). The participants were 113 ninth graders at a junior high school (36 for Low group, 39 for Mid group, and 38 for High group) in Changhua County. The study made use of a cloze test to elicit data from the subjects’ responses and explored the research topics: (1) the prediction of the Aspect Hypothesis on simple past, (2) LI influence on the use of simple past, and (3) the relation between learners5 L2 proficiency and their simple past use among the categories of lexical aspect. Based on the statistic outcomes，the results of the study supported the prediction of the Aspect Hypothesis on simple past. That is, simple past initially associated with telic verbs, then spread to activities, and finally extended to states. Meanwhile, this study found the perfective marking -le in Chinese might cause a positive transfer effect on the use of simple past in English. In addition, as learners5 general English proficiency increases, the effect of the Aspect Hypothesis will become weakened on learners5 use of simple past. At last, through the study, the researcher also provided some suggestions and implications for future directions of studies and English instruction.