The principle of Formulating Hangeul
The alphabet is famous as a phonemic writing system in which the letters are grouped into syllables of approximately the same size and shape as monosyllabic Chinese characters, which are often interspersed with Hangeul in what is known as "mixed script."(Modern Hangeul is not strictly phonemic but morphophonemic, so that written syllables no longer correspond exactly with spoken sounds.) Hangeul is recognized worldwide as a highly scientific writing system that is both an alphabet and a syllabary.
Another unusual feature of Hangeul is that the shapes of its letters were modeled on the human articulatory organs and the three basic components of the universe: heaven, earth, and man. King Sejong and his scholars conceived of a syllable as comprising initial consonant(s), medial vowel(s), and final consonant(s). While other alphabets arrange their letters in horizontal or vertical rows, Hangeul forms them into squares, each representing a syllable, which allows both accurate representation of the Korean language and ease of learning.
Consonants are divided into five classes modeled on five articulatory positions. The basic forms are the "molar"(velar) ㄱ (g), in the shape of the root of the tongue closing the throat; the "lingual"(alveolar) ㄴ (n), in the shape of the tongue touching the inner upper gum; the labial ㅁ (m), in the shape of the mouth; the "incisor" dental fricative) ㅅ (s), in the shape of a tooth; and the laryngeal ㅎ (voiced h), in the shape of the throat. In each class, phonemes that are "stronger" than these basic forms are written with one or two additional strokes. For example, the "lingual" ㄴ (n) is "strengthened" to ㄷ(d), which in turn becomes ㅌ (aspirated "t").
"Medials"(vowels) are divided into yang, yin, and combined yang-yin categories, and the three basic vowels are associated with heaven ( . , a), earth ( ㅡ, eu), and man ( ㅣ, i). The other vowels (ㅏ,ㅑ,ㅓ,ㅕ,ㅗ,ㅛ,ㅜ,ㅠ) are formed by combining these basic vowel shapes. For example, in ㅗ (o), ㅛ (yo), or ㅑ (ya), the basic vowel shape "." is added once or twice above the basic vowel shape "ㅡ" or to the right of the basic vowel shape "ㅣ" In ㅜ (u), ㅠ (yu), and ㅕ (yeo), the basic vowel shape "." is added once or twice below the basic vowel shape "ㅡ" or to the left of the basic vowel shape "ㅣ". These design principles may not be self-evident, but modern linguists concur with the concept of vowel harmony and the categories of strong vowels, weak vowels, and neutral vowels.
"An Explanation of the Initials" refers to the ancient Chinese rime books, or phonological treatises, which divided each syllable into its initial consonant and the remainder, comprising a vowel and sometimes a final consonant. For example, the initial consonant ㄱ (g) combines with the medial vowel ㅜ plus the final consonant ㄴ (un) to make the syllable 군 (gun), and other initials work the same way.
A highly scientific orthography which can readily transcribe any word or sound in the Korean language, Hangeul was originally intended for translating the Chinese classics, highly regarded in Confucian Korea, so that these revered texts could be more widely read. For example, a translation of the Chinese "Four Books and Five Classics" was begun in Sejong's reign and completed under King Seonjo in the late 16th century. Novels written in Hangeul reached a burgeoning audience, primarily middle-class and female, adding a new dimension to Korean culture. In modern times, Hangeul gradually replaced Chinese characters as the main system of writing in Korea.
