Focusing on the Korean auxiliary verb pair -e twu- and -e noh-, this study attempts to introduce a corpus analysis to detect the distinctiveness of two synonymous constructions. As the Korean verb twu- 'to put' and noh- 'to put' are considered synonymous, the corresponding auxiliary verb pair -e twu- and -e noh-also have been commonly assumed to be synonyms. In this study, the syntactic and semantic features of the Korean auxiliary verb pair -e twu- and -e noh are examined based on the actual usage in Korean corpus data. Using methods of distinctive collexeme analysis, two main questions are investigated: whether both auxiliary verbs can be used interchangeably as synonyms and what their distinctive features are. The results of the analysis provide three semantic groups of main verbs that attract to each auxiliary verb: verbs of preservation, cognitive activities and releasing for -e twu-; verbs of motion, dispersion and creation for -e noh-. Based on the semantic analysis of the co-occurred main verbs, this study argues that each auxiliary verb in question has its own distinctive semantic features; and that distinctive semantic features of main verbs are influential factors in choosing one particular auxiliary verb from two synonymous auxiliary verb constructions. This study also explored how the distinctive collexeme analysis could benefit to teaching two synonymous constructions and the potential of cognitive linguistic approaches on Korean language instructions. Based on the result of the case study, I suggested that the list of distinctive collexemes could provide a practical application in language instruction for the Korean auxiliary verb pair, which has similar semantic features.