The present study searched for a function-focused syntax that would reflect actual Korean usage, shifting the focus of the Korean grammatical paradigm away from morphology, category and onto function. The present study first examined the existing literature on syntax research to compare various things, such as current issues in the subjects being studied, research methodologies, and categorical intersections, in the search for a function-focused Korean syntax. Then it probed the possibility of establishing a function-focused syntax. The current Korean syntax is focused on morphology and category such that the important grammatical units are morphological units such as particles and endings. However, Korean periphrastic construction has various grammatical functions, such as denoting case, tense, aspect, voice, manner, infinitive, and clausal conjunction. Previous research focusing on function mostly concentrated on the functional commonalities of a single grammatical morphological unit, such as a particular particle or ending, and periphrastic construction, but they did not differentiate between the layers. When deciding which grammatical units should be included in a function-centered syntax, single grammatical morphological units and periphrastic constructions must be differentiated. Compared to a single grammatical morphological unit, periphrastic constructions’ forms are unstable and, in many cases, their functions cannot be categorized. Therefore, it must be acknowledged that there are many problems in dealing with single grammatical morphological units and periphrastic constructions in the same layer. One problem in describing function-focused Korean syntax is how to deal with cases in which the same function is fulfilled by two different morphological units. In the existing category-focused syntax, the relationships between morphological units that belong in different categories, even when they have the same function, are not considered to be important. The present paper examines the relationship between morphological units of various categories, such as particles, endings, and adverbs that function as conjunctions, and in this context discusses the grammatical category intersection problem. Conjunctive endings, conjunctive adverbs, and conjunctive particles not only serve as conjunctions, but they can also describe the hierarchical relationship between the two units. Therefore, the commonalities and differences between endings, adverbs, and particles must be examined in more detail. Furthermore, it is also necessary to examine the relationships between morphological units with similar meanings within each category. Function-focused grammatical systems have been ignored partly because the terminology used to describe these systems and the systems themselves are clearly different than existing grammatical descriptions. Recently, there has been an increasing amount of research that inductively organized the results of corpus analyses. However, the results of such research were excessively inductive and subdivided and so did not converge into a deductive system, causing more confusion. Therefore, the present study proposed that a function-centered syntax must be based on existing categories and systems, rather than on the negation of category- and morphological unit-centered syntaxes.