本文檢視明清的閩南語戲文《荔鏡記》（又名《荔枝記》）和當代的 閩南語故事集，梳理閩南語義務情態動詞「愛」（ai3）之發展及演變， 用以解釋主觀化機制在義務情態詞衍生過程中的重要性（Traugott 1989, Langacker 1990)。本研究發現，閩南語「愛」在晚近才出現義務 情態用法，這應是由同樣牽涉「力互動」（force interaction）之表意圖 的動詞「愛」（Talmy 2000）經由主觀化機制變化而成。此變化是建立 在表意圖的「愛」與義務情態「愛」之間整齊對應的動力結構上，而 此平行結構亦證明語意力互動的關係在語言變化過程中受到保存。一 般認為主觀化機制與認知情態詞的產生有關（Traugott 1989, Sweetser 1990），而本研究之發現則可驗證主觀化機制是衍生涉力情態詞的一個 共同驅動過程。

This paper aims to show the importance of subjectification (Traugott 1989, Langacker 1990) for the emergence of deontic modals with the development of the deontic modal ai3 in Southern Min. Materials under examination are early texts of Southern Min in the playscripts of Li Jing Ji ‘The Legend of Litchi Mirror’ and a collection of folk stories in contemporary Southern Min. The deontic modal ai3 in Southern Min is assumed to have developed from the intentional ai3 through subjectification on the basis of their parallel force-dynamic structures which represent the preservation of their force interactions throughout the development of the deontic modal ai3 (Talmy 2000). Because subjectification is also known to contribute to the emergence of epistemic modals (Traugott 1989, Sweetser 1990), it can then be seen as a general process through which force-involved modals can emerge.