Chinese characters were introduced early into Korea. They were used extensively in Koguryŏ, Paekche and Shilla, and by the time of Unified Shilla (668-935) the educated class wrote Chinese poetry.
Classical Chinese was the cornerstone of a good education. Skill in poetic composition was a ticket to preferment. Chinese continued to be the language of government and literature until the end of the nineteenth century when the rising tide of nationalism led to a rejection of Chinese influence and the promotion of Korea’s native script. Sejong’s scholars invented the vernacular script in the fifteenth century, but the literati never accepted it as a cultivated form of expression, understandably so, since Chinese was a scholar’s rice bowl. In Kim Sakkat’s time, the vernacular script was still called ŏnmun or vulgar language, suitable for those who by sex, class or lack of ability were deemed unsuited to formal study. The various categories of Chinese verse—Four-syllable Verse, Old Style, Modern Style, Lyrics Meters, Dramatic Verse and Dramatic Lyrics—were all read in Korea, but the vast bulk of written hanshi was either Old Style (Koch’e shi) or Modern Style (Shinch’e shi). Old Style is verse in five and seven character lines, which does not follow the rules of tonal parallelism; Modern Style is verse in five or seven character lines, which follows the rules of tonal parallelism. The main divisions of Modern Style are Regulated Verse (Yulshi) and the Quatrain (Chŏlgu). A poem in Regulated Verse has eight five or seven character lines, observes tonal parallelism, employs a single rhyme at the end of the second, fourth, sixth and eighth lines (rhyme at the end of the first line is optional) and shows verbal parallelism in the second and third couplets. The Quatrain uses five or seven character lines, observes tonal parallelism, and employs rhyme at the end of the second and fourth lines (rhyme at the end of the first line being optional). Regulated Verse and the Quatrain have a fourfold structure: theme (ki), development (sŭng), anti-theme (chŏn), and conclusion (kyŏl). Even today this four-fold structure informs all Korean thinking on the composition of poetry.
Regulated Verse was so difficult that many Korean poets continued to write Old Style. There was plenty of precedent for this in China, where the great Li Bai used Old Style by choice. Chinese has four tones that differ from each other in pitch, length, and movement. In determining meter, the first tone is regarded as level; the other three are regarded as deflected. Level means the voice remains on an even keel; deflected means the voice moves up or down. To find out if a character is level or deflected, you simply look up the dictionary. Since hanshi was recited in the Korean pronunciation of the characters, the role of tone in hanshi must have been very different from the role of tone in Chinese verse. In fact, at the risk of being charged with heresy, one is tempted to say that tone had no role in hanshi other than to demonstrate the technical mastery of the poet over his craft. Observing tonal patterns was a formal controlling mechanism that gave face to the poet but provided no semantic impact. Similarly matching the rhymes had no semantic function. Problems of tone and rhyme were solved by simply consulting the dictionary. The rhyme dictionary that is still used was finalized in the reign of Chŏngjo.
Classical Chinese poetry used all the sound resources of the language including assonance and alliteration. Again because hanshi was recited in the Korean pronunciation of the characters, it is not clear how hanshi poets handled such prosodic features. Chinese has no cases, tenses or gender. Position in the line determines whether a character is a verb, noun, adjective and so forth. Chinese does not have plural suffix markers—you are not sure whether the poet is looking at one heron or ten—and Chinese often drops the subject of the sentence. Interestingly, Korean has similar ambiguities: there are no plural markers (the plural marker tŭl is of comparatively recent vintage), and pronouns and subjects of sentences are often dropped.
Finally, it should be noted that Korean hanshi poets continued to write classical Chinese (munŭn mun) throughout the nineteenth century; they never attempted the modern Chinese idiom (paekhwa ch’e).