Hanja
Although a phonetic Korean alphabet, now known as Chosŏn'gŭl or Hangul, had been created by Sejong the Great, it did not come into widespread official use until the late 19th and early 20th century. Thus, until that time it was necessary to be fluent in reading and writing Hanja in order to be literate in Korean, as the vast majority of Korean literature and most other Korean documents were written in Literary Chinese, using Hanja as its primary script. Today, a good working knowledge of Chinese characters is still important for anyone who wishes to study older texts (up to about the 1990s), or anyone who wishes to read scholarly texts in the humanities. Learning a certain number of Hanja is very helpful for understanding the etymology of Sino-Korean words, and for enlarging one's Korean vocabulary. Today, Hanja are not used to write native Korean words, which are always rendered in Hangul, and even words of Chinese origin—"Hanja-eo" ()—are written with the Hangul alphabet most of the time, with the corresponding Chinese character often written next to it in order to prevent confusion with other characters or words with the same phonetics.
Origin of Hangul
The Korean alphabet is a featural alphabet written in morpho-syllabic blocks, and was designed for both the Korean and Chinese languages, though the letters specific to Chinese are now obsolete. Each block consists of at least one consonant letter and one vowel letter. When promulgated, the blocks reflected the morphology of Korean, but for most of the fifteenth century they were organized into syllables. In the twentieth century the morpho-syllabic tradition was revived. The blocks were traditionally written in vertical columns from top to bottom, although they are now commonly written in horizontal rows from left to right as well. Spacing has been introduced to separate words in the Western fashion, and punctuation to indicate clauses and sentences, so that the Korean alphabet now transcribes Korean at the levels of feature, segment, syllable, morpheme, word, clause, and sentence. However, the suprasegmental features of tone and vowel length, seen as single and double tick marks to the left of the syllabic blocks in the image in the next section, have been dropped. Six new letters, including two of Sejong's which had become obsolete, were introduced in North Korea in 1948 in order to make the Korean alphabet a perfect morphophonological fit to the Korean language, but they were soon discarded.