華語助動詞「要」的功能主要有三種：欲求情態、義務情態、以及表鄰近未來（immediate future）；三者雖來源相關但卻隨其語意語法特徵的不同而分布相異，因此得以違反形—義對應原則在共時平面上用「要」的形式並存。本文中我們主要以「動態力」理論（Force Dynamics, Talmy 2000）中主語上的正反作用力為區辨性特徵、以各功能之主觀化程度與方式的不同為輔助條件、並對照閩南語情態助動詞「愛」與「卜」的發展脈絡與分布限制，來探討華語助動詞「要」之各功能的分工與互補。我們發現，由於「愛」與「卜」的功能在華語由「要」囊括，因此後者的解讀需較多限制與提示，亦即「動態力」與主觀化的概念會對「要」的辨義更有幫助。

Mandarin polysemous auxiliary yao4 (要) involves three main semantic functions: volitive modality, obligative modality, and immediate future, which are closely interrelated in diachronic development and synchronically complemented with each other regarding semantic and syntactic distributions; those distributional significances enable the three polysemous functions to be represented by one shared form yao4 (要) without causing misinterpretations from the violence of form-meaning correspondences. In our study, it is found that the presence or absence of the two force-dynamic features [+F] (reacting force) and [−F] (counterforce) (based on Force Dynamics, Talmy 2000) on the grammatical subjects can help distinguish the multi-functions of yao4 (要). Furthermore, varying degrees or types of subjective involvement in the completeness of propositional meanings are beneficial in disambiguating the polysemous usages of yao4 (要) as well. In particular, to make the distributional patterns of yao4 (要) clearer, the dialectal analysis of the two modal auxiliaries ai3 (愛) and beh4 (卜) in Southern Min were added to do comparison with the behaviors of polysemous yao4 (要); the result showed that while arbitrariness are reduced in Southern Min because the functions of polysemous auxiliary yao4 (要) are divided by ai3 (愛) and beh4 (卜), there need to be more distributional restrictions or conversational cues for Mandarin users to elicit adequate interpretations of the multi-functional yao4 (要); therefore, the notions of Force Dynamics and Subjectification (Langacker 1990) could be more useful in disambiguating the functions of yao4 (要) in Mandarin.