The purpose of this paper is to understand the properties of the plural marker 'deul' and to discuss what qualifications 'deul' has as a subjecthood test. Matters to be noted when using 'deul' as a subjecthood test are as follows. First, 'deul' combines well with nouns with high-animacy, among which are human nouns. Second, the event plural 'deul' is consistent with a predicate that can be interpreted distributionally. In Chapter 3, subjecthood was verified for the multiple subject constructions presented in the previous discussion. As a result, problems arising from the use of 'deul' as a subjecthood test in existing discussions were revealed, and subjecthood verification results different from previous discussions were derived.