This study examines the formation of the dummy pronoun "ta" 他 in "he ta ge tongkuai" 喝他個痛快 '(Let's) Drink to our heart's content!' from a diachronic syntactic perspective, and it also discusses other related constructions with the dummy pronoun ta. The results suggest that, although there are some similarities and differences among these constructions, they can be divided into two categories: those related to double object constructions (e.g., "he ta ge tongkuai" and "gei ta ge hun" 給他 個混'(Let's) Muddle along!'); and those associated with single object constructions (e.g., "he ta san bei" 喝他三杯 '(Let's) Gulp some wine down!' and "guan ta san qi ershiyi" 管他三七二十一 '(Let's) Forget about it and let it rip!'). For the former category, we propose that ta in "he ta ge tongkuai" was analogized from a double object construction, which resulted in a formal object ("ta") being inserted. In the latter case, "ta" was grammaticalized from a third-person indefinite pronoun which had been an appositive in Middle Chinese. Constructions with the dummy pronoun "ta" are all strongly speaker-oriented, which may be due to the fact that "ta" evokes a different locus, that is, a concept of a space that does not coexist with the speaker.