The Korean double nominative construction shows many characteristics distinguished not only from subjectobject clauses but also from nominative complement constructions. Specifically, the initial NP of the construction exhibits properties that are attributed to a subject in terms of object to subject raising and caki binding. Embracing the traditional ideas such as Major Subject and the sentential predicate (Park 1981, Yoon 2004), the initial NP of the construction is suggested to be predicated by a sentential predicate. Therefore, in this approach, the NP is considered a grammatical relation that exists in addition to the subject, i.e., sentential specifier. This paper also shows how the proposal is neatly dealt with by Sign-Based Construction Grammar (Boas and Sag 2012).