二語習得中最著名的錯誤之一為不及物動詞的過度被動化。雖然很多理論提出不同的見解解釋二語學習者為何會犯下這些錯誤，但是非常少研究發現二語學習者犯的錯誤在不同的不及物動詞間有非常大的差異。Sorace的分裂不及物動詞階層理論將不及物動詞加以分為「核心」、「次核心」及「邊陲」三個階層。近來，這個理論已被用來應用在二語學習者在不及物動詞上的習得狀況。本研究應用此理論來重新檢視中文母語者在學習英文上的過度被動化現象。實驗要求受試者用英文描述含有不及物動詞的圖片。結果發現受試者在「次核心」及「邊陲」兩個階層所犯的過度被動化錯誤遠多於「核心」。此外，研究結果也支持非賓格理論。

One of the most well-known errors in second language acquisition is overpassivization of intransitive verbs. Even though many theories have been proposed to explain the nature of second language (L2) acquisition, very few can explain the huge verb variation found in these studies. Sorace’s Split Intransitivity Hierarchy was originally proposed to explain native speakers’ auxiliary selection across unaccusative and unergative verbs. Verbs in the hierarchy are classified into “Core,” “Less Core” and “Periphery” groups. Recently, this theory has been extended to explain L2 learners’ acquisition of intransitive verbs. The current study re-examined overpassivization errors among L2 Mandarin learners with three different proficiency levels by looking at whether the error numbers they produced conform to the predictions of Sorace’s Split Intransitivity Hierarchy and Perlmutter’s Unaccusative Hypothesis. Participants were asked to describe pictures using target intransitive verbs, including both unaccusative and unergative verbs. The results were in support of Sorace’s hypothesis. Subjects produced significantly more errors in “Periphery” and “Less Core” categories than in the “Core” category. In addition, the results of the experiment also supported the Unaccusative Hypothesis.