The purpose of this study is to examine the process of establishing the morphemes '-i-, -hi-, -li-, -gi-' in North Korean grammar and then we determine whether it is appropriate to set the voice category of adjective with verb. In North Korean grammar, '-i-, -hi-, -li- , -gi-' are grouped together with particles(조사) and endings(어미) and set as To(토) categories. It seems to be due to an error caused by unreasonably emphasizing the individual characteristics of Korean as an agglutinative language. We suggest a distinction between the affixes of '-i-, -hi-, -li-, -gi-' and To(토). They have the characteristics of derivational affixs and inflectional affixes, so it is appropriate to set up them as grammatical(or syntactic) lexical affixes. According to the previous studies such as Ju, Si-Gyeong(1910) and Kim, Doo-Bong(1922), the function of affixes was approached and understood based on the root of the word, and North Korean grammar also follows this. However, it is difficult to capture the morphological process of affixation. Therefore, this paper believes that, as Hwang, Hwa-Sang(2018), it is necessary to understand the derivation process of affixes with derivatives-driven approach. It is more consistent with the language reality of Korean. It explaines the commonality of the process in which intransitive verbs and adjectives are transformed into causative Verbs.