The purpose of this paper is to explain the new use of the honorific prefinal ending ‘-si-’ observed in modern Korean, called ‘respect for the nonhuman object’ or ‘respect for the situation subject,’ from the perspective of language change. Using specific examples used by Korean speakers in various areas, I looked at the fact that the new use of ‘-si-’ goes beyond a simple expansion of existing usage and shows the beginning of a change in function. The ‘-si-’ used to respect the topic of double subject constructions is now also used to respect the vocative phrase, which refers to an outside hearer independent of the meaning of the sentence. I interpreted it as one of the changes in the syntactic function of ‘-si-’. If the function of ‘-si-’ that respect the hearer outside of the sentence may be maintained, the ‘-si-’ may change into a form completely used for the hearers like the object-respecting morpheme did.