這篇文章有三個目的：一是探討客語中常見的幾個介系詞di、do、bun、lau、tung、ziong 的用法，及其相關片語之句法結構。二是將這些常見的介系詞片語依照其功能及位置區分為四大種類。第三是以優選理論分析這些介系詞片語在句式中的分布，並歸納成制約條件排序的理論。優選理論將分為兩個步驟進行分析，第一步先將優選理論應用在語意學的範圍，藉此指定每個介系詞片語的補語或附加語功能；第二步運用優選理論於句法範疇，藉由概括對整制約條件間的排序，預測屬於每一種類介系詞片語允許且適當的句法位置。

This paper has three purposes. The first purpose is to examine the uses of the prepositions: di, do, bun, lau, tung, ziong, and generalize an overall structural pattern for the Hakka VP involving prepositional phrases. The second purpose is to distinguish between the PPs functioning as complements and adjuncts of the verb, and argues that the two types of PPs may occur in four different syntactic positions depending on their syntactic and semantic functions. The third purpose is to formulate an Optimality Theoretic analysis to account for the different positioning of PPs. The analysis is achieved through two rounds of OT evaluation. The first round is based on the semantic OT, by which each PP receives its complement or adjunct interpretation when appearing in the VP. The second round is syntactically oriented. By proposing various manifestations of Generalized Alignment Constraints for complement PPs associated with different semantic functions and adjunct PPs exhibiting a relatively more peripheral relation with the verb, this paper will show that the interaction of these alignment constraints provides an alternative account for the distribution of the four different kinds of PPs.