A study of the reflects of the Sino-Korean in conjunction with the ancient Chinese initials system, analyzing and synthesizing the extracted data, enables us to point out the principal and general tendencies operations in the correspondence:
(1) The reflects of Sino-Korean to the initials system is based on the ancient Chinese in the Chieh-Yun period; however, the phonetic details of the ancient Chinese were either abandoned or simplified so as to accord with the phonetic laws of the Korean language. That is to say, those phonetic distinctions based on a division of the internal of the various sounds, such as the linguals, dentals, etc., were in principle neglected, since to retain those reflects would have suggested the previous old stratum of the complicated consonant system in the T'ang Chinese. As regards the initials, the nasal "ng-" of the initials "ngji(疑)" and the glottal ".-" of the initial "jbng"(影) were assimilated to the ancient Sino-Korean equivalent to the initials "jiu"(喩). Those changes can be found in the study of the Chinese phoneme; but they could also the regarded as the laws of substitution based on the initials laws which are a phonological peculiarity in the Korean language.
(2) We are convinced that originally there was no distinction between the voiced and voiceless in the consonant system of the Korean language. Accordingly, the voiced sounds were in principle joined with the voiceless sounds. That is to say, in the plosives, the voiced "g-/d-/b-" has been realized as the voiceless "k-/6-p-," and also in fricative "z-" and the suttural "h-" has been joined with "s-" and "h-" respectively. We can exemplify a few peculiar reflects which form exceptions to the above principle: in the affricates, the initial dziwong(從) of the voiced sounds was reflected as "ㅈc", joining mainly with the initial stiang(精) of the agnate voiceless, while conversely, the initials dziwang(狀) and dzen(神) of the voiced sounds were also reflected as "ㅅs-", joining mainly with the voiceless initial "siam"(心) of the fricative.
Those phenomena are reminiscent of the old stratum in the T'ang Chinese, which apparently was frictionized. Joining with the initial "siam"(心) together with the initial "zian"(禪) of the voiced sounds, after the exclusion of the voiced plosive "d-". Consequently, it is possible to say that the initial "dziwang"(狀) has also been frictionized under the same conditions, since the initial "dzen"(禪) and "zian"(禪) enter and leave one another frem the fan-ts'ie(反切) of a Hui-lim's(慧琳) commentaries to the Chinese Tripitaka.
(3) In ancient Chinese, the nasal ㄴn/ㅁ m and the liquid r regularly show a correspondence identical to that in the Korean language. The initial "ngji"(through the particularity of the Korean Language) was substituted for the initial "jiu" thereby losing the character of the nasal in the initial through the particularity of the Korean language.
In the initial "nziet(口), the voiced fricative "ㅿz-" shows a superiority. We are convinced that it would not retroact even before the era of Silla(新羅), but be caused by the phonological changes arising from the dialect of the central districts of Korea, through the influence of the Chinese kaif. dialect in the era of Koryo(高麗): the initial nziet originally became the initial jiu(喩) of the nz->z->j-, losing the nature of friction under the influence of the backward-following vowel i/. Therefore, ㅿz- ruled on the consonant system of Hunmin Chongum 訓民正音 and the double-faced phnomena of ㅿz- /ㅇ-in the Sino-Korean readings indicate the new stratum which appeared in the era of Koryo, also in the Sino-Korean readings there is evidence of the new and old strata together.
(4) In ancient Chinese, the reflects of the aspirated sounds have been reflected with complicated appearances in accordance with a variety of the sounds: in the gutterals, it is reflected as voiceless "k-" on the other hand, in the inguals and labials, it becomes liquid on both sides of t-/t- and p-/p-/.
Those phenomena described above, demonstrate that there was no opposition between aspirates and non-aspirates in the phonological system of ancient Korean. Furthermore, we are able to assume that there were never any aspirated sounds in the vocabulary of the Korean Language have been shown to have appeared in the era after the middle of the Yi Dynasty.
If this is so, it may be considered to have begun with the development of aspirated sounds through the influence of Chinese pronunciation and that through its gradual penetration into the vocabulary of the Korean language it brought about phonological opposition.
One more point which suggests that Sino-Korean was based on early ancient Chinese, is the fact that the dentals completely maintained "t-" up to the end of Koryo and/ or the beginning of the Yi Dynasty. With the Sino-Korean readings of Hunmong Chahoe 훈몽자회 in mind, cannot find that the dentals have been palatalized. From data of the latter period, a palatalization of the dentals was seen to be dependent upon the phonological changes which have caused the dentals in modern Chinese to become affricates.