In Korean, which linguistically belongs to the agglutinative language type, the forms of particles and verb endings are well-developed. In the conjugation of verbs, various substitution patterns emerge during the combination of stems and endings. However, irregular substitution patterns, where stems and endings take different forms during conjugation, are commonly observed and have been traditionally addressed as irregular conjugations. Modern Korean includes various vocabulary items demonstrating irregular conjugations, and these patterns exhibit diversity depending on regional dialects. This study focuses on a geolinguistic analysis of 77 surveyed points from the National Social Science Foundation of China Key Project, "Chinese-Korean Dialect Atlas." The study centers on the 'ㅅ' irregular verbs '낫다(愈)' and '긋다(劃).' Initially, the paper confirms diachronic changes through literary materials and then examines usage patterns and specific dialectal forms in Chinese-Korean dialects. The conjugation patterns of 'ㅅ' irregular verbs reveal that '낫다(愈)' can be categorized into 'ㅅ' regular conjugation, 'ㅅ>ㅈ' regular conjugation, 'ㅅ>∅' irregular conjugation, and cases where regular and irregular conjugations coexist. Similarly, '긋다(劃)' is divided into 'ㅅ' regular conjugation, 'ㅅ>∅' irregular conjugation, and cases where regular and irregular conjugations coexist. During irregular conjugations, variant forms experiencing vowel deletion are observed in environments of vowel collision. Notably, in the case of '긋다(劃),' some dialects exhibit characteristics of vowel darkening during both regular and irregular conjugations. Finally, the paper briefly discusses the geographical distribution patterns of regular and irregular conjugations and explores the reasons behind the observed dialectical distribution characteristics.