This article aims to elucidate the syntagmatic order and constraints of auxiliary verb phrases in Korean. It discusses the structures and meanings of auxiliary verb phrases, focusing on the ‘-eci-’ and ‘-key toy-’ constructions. The aim is to explore the interrelation between their structures, meanings, and integration relationships. The ‘-eci-’ construction is divided into passive and inchoative constructions, both sharing the semantic feature of [-control]. The ‘-key toy-’ construction shares semantic similarities with the ‘-eci-’ construction but differs structurally and forms complex sentences. Furthermore, the semantic and syntactic similarities and differences between these two constructions become evident in their integration with other auxiliary verb constructions. For example, when the ‘-eci-’ construction is interpreted as passive, it maintains a fixed order, whereas the ‘-key toy-’ construction exhibits more flexibility in word order. However, the ‘-eci-’ and ‘-key toy-’ constructions can have common interpretations depending on their scope.