本文針對客語「□」字句多種句法結構及語意內涵提出以下的分析：首，「□」經過兩階段語法化的過程，先由動詞發展為介詞，再進一步發展成連接詞，其語意也從「摻合、攪拌」擴展到「伴隨義」，再擴展為「連接義」。同時藉助隱喻強化的功能及事件架構中參與角色的隱現與否，「□」從伴隨義擴展出其他五種的語意，角色的隱現與否。

　　　　　With regard to the meaning relatedness of the multiple grammatical and semantic functions associated with LAU, this study has the following proposals. First, it is claimed that LAU undergoes a two-step grammaticalization process, decategorizing from a verb to a preposition and subsequently into a conjunction. Along with the structural decategorization process, LAU extends its predicate meaning denoting to mix to its comitative preposition meaning denoting together-with, and then into conjunction meaning and. Second, it is argued that through the mechanism of metonymic strengthening and underspecification of participant roles in an event frame, each of the various senses can be induced given appropriate context. Specifically, the goal sense is strengthened through the implied inference of the comitative sense when the predicate is a verb of communication. The source sense, which denotes the opposite direction of the goal, comes out of an event frame that involves predicates of taking away. Then both the goal sense and the source sense can feed the emergence of the benefactive sense. Finally, two alternative paths are proposed to account for the emergence of the patient sense-either from the source sense or from the benefactive sense. Henceforth, the meaning extension of these different semantic functions associated with Hakka LAU is accounted for plausibly.