能願動詞「可以」之語義功能複雜(呂叔湘1980),時常造成華語學習者使用偏誤(鄧守信2018)。為觀察學習者整體偏誤情形,本文分析總字數約三百萬字的「TOCFL華語學習者語料庫」,以非母語的華語學習者作為研究對象,考察其在考試作文當中使用「可以」各語義的分布及其偏誤情況,並依程度歸納偏誤類型,進行分析,尋找4個級別的學習者發生偏誤的可能原因。本研究表明:在「遺漏」、「多用」、「錯用」和「錯序」四種偏誤中,「多用」偏誤為學習者普遍出現的問題,起因於學習者使用了語義重疊或是語義衝突的詞彙。而另一常見的「錯序」偏誤,筆者認為起因於學習者誤將能願動詞視為英語情態助動詞的形式,而固定置於動詞前面,無法隨著動詞組附加語位置的副詞或介詞組變換位置,「錯序」偏誤因而發生。整體而言,非母語的華語學習者隨著華語程度的增加,對「可以」的語義以及其他詞彙的掌握逐步提升,相關的偏誤率因而呈現下降的趨勢。然而,對詞性的認知錯誤,可能是導致「錯序」偏誤不降反升的因素。除偏誤分析外,鑒於教材可能是影響學習者習得的因素,本文亦探討華語教材中「可以」的教學語法,就各語義的教學編排展開討論。
The study reports an error analysis of Chinese modal verb keyi by learners of L2 Chinese based on TOCFL Learner Corpus. It aims at categorizing, analyzing, and accounting for the error types of keyi made by learners at the beginning (A2), the intermediate (B1), the high-intermediate (B2), and the advanced level (C1). The results show that among the four error types-missing, redundancy, misselection, and misordering-redundancy is the most common error, which is likely due to learners' lack of adequate vocabulary knowledge and therefore misusing keyi with lexicons that have identical or clashing functions. However, as their L2 Chinese proficiencies increase, learners will develop better commands of the meanings and functions of keyi and related errors decrease accordingly. Nevertheless, another common error, misordering, has not decreased but increased with the growth of learners' proficiencies. The persisting error is suggested to result from learners' mistaking modal verb keyi for an auxiliary in conjunction with main verbs, regardless of other adverbs or prepositional phrases that are left adjoining adjuncts to VPs. This study then deliberates on the sequencing issues pertaining to different meanings of keyi in a pedagogical grammar.