本研究探討華語情態詞「應該」於第二語言習得中的困難來源，並從介面假說的觀點說明，偏誤並非單純詞彙或句法問題，也可能涉及語義多義性與語法—語用介面整合的挑戰。「應該」涵蓋義務義與認知推測義，習得過程中涉及語義判讀、句法配置與語用推論等面向的整合。本研究以《TOCFL學習者語料庫》為基礎，分析L1日語與L1英語的華語學習者在不同程度使用「應該」的表現，並將偏誤分為「遺漏」、「冗贅」、「錯序」、「誤選」、「混合」與「搭配不全」六類。研究結果顯示，日語組與英語組的學習者，在推測義「應該₂」上的偏誤率皆高於義務義「應該₁」，顯示推測義相較於義務義更容易造成使用困難。兩組的偏誤類型皆以「遺漏」與「搭配不全」為主。此外，日語組以「錯序」為第三大偏誤類型，英語組則以「誤選」居第三。此一分布顯示，兩組學習者皆因母語情態形式與華語「應該」多義結構之間難以完全對應，但其具體偏誤表現因母語背景而有所不同。本文認為，「應該」的習得困難可由語義多義性、語際映射不對稱，以及語法—語義—語用資訊整合負荷加以解釋。研究結果可為華語情態詞習得研究與相關教學設計提供參考。

This study investigates the sources of acquisition difficulties associated with the Mandarin modal verb yīnggāi (‘should’) in second language acquisition. From the perspective of the Interface Hypothesis, it argues that learners’ errors do not arise merely from isolated lexical or syntactic problems, but from challenges related to semantic polysemy and grammar–pragmatics interface integration. Yīnggāi encodes both deontic obligation and epistemic inference, requiring learners to coordinate semantic interpretation, syntactic placement, and pragmatic inference. Based on the TOCFL Learner Corpus, this study analyzes the use of yīnggāi by Japanese-L1 and English-L1 learners of Mandarin across proficiency levels. Learners’ errors are classified into six types: omission, redundancy, misordering, misselection, blend errors, and incomplete collocation. The results show that both Japanese-L1 and English-L1 learners produced higher error rates with epistemic yīnggāi than with deontic yīnggāi, indicating that epistemic uses are more difficult than deontic uses. Omission and incomplete collocation are the most frequent error types in both groups. In addition, misordering is the third most frequent error type among Japanese-L1 learners, whereas misselection ranks third among English-L1 learners. This distribution shows that both groups face difficulties because the modal forms in their first languages do not fully correspond to the polysemous structure of Mandarin yīnggāi, but their specific error patterns differ according to L1 background. This study suggests that the difficulty in acquiring yīnggāi can be explained in terms of semantic polysemy, asymmetric cross-linguistic mapping, and the information-integration demands involving grammar, semantics, and pragmatics. The findings have implications for research on the acquisition of Mandarin modal verbs and for pedagogical design.

中介語; 介面假說; 偏誤分析; 第二語言習得; 華語情態詞; 「應該」

error analysis; Interface Hypothesis; interlanguage; Mandarin modal verbs; second language acquisition; yīnggāi