本研究旨在探討雅美語雙及物結構是否也有與英文，及其他語言如日語、希臘語、國語，一樣有與格轉換的語言現象。雅美語有一特別的強調系統可將名詞組移到主詞的位置上。在探討雅美語的雙及物結構前，必須先探討幾個問題。首先，研究名詞組的格位標記是否會因動詞的性質（動詞的及物性、動詞的論元結構）不同而有所改變，其次，提出論證證明強調系統並不適用於形容雅美語特殊的移位系統，而語態系統較能更進一步的形容此一名詞移位現象。最後，提出雅美語並不是一個作格語言，而是一個valency-neutral的語態系統。解決這些問題後，發現雅美語中也有類似英文中的與格轉換的語言現象，此一發現也驗證了Harley的提案，擁有“有”動詞的語言就會有與格轉換的現象。 / The aim of the present study is to examine the existence of dative alternation in Yami, a language with a rich case marking system, that is similar to Japanese and Greek which are both reported to have dative alternation, as well as very unique ‘focus’ systems that can promote any argument into the subject position. Several issues have to be addressed: first, the case marking on the nominal is investigated in four most commonly observed ‘focus’ constructions from various aspects including degree of transitivity, thematic structure, and event classes,…etc; second, the term ‘focus’ is misleading and is identified as ‘voice’; third, arguments against Yami as an ergative language and supports for a valency-neutral voice system are provided.　Once these basic linguistic properties have been clarified, an examination of trivalent verbs shows positive evidence of dative alternation in Yami. Dative alternation is found with the two trivalent Yami verbs meaning ‘distribute out/give out’ and ‘mail’. This finding is in accordance with Harley’s proposal of the co-existence verbal HAVE and dative alternation, and also suggests that dative alternation is not a language-specific property.