Claim: South Korea's main language is from 1443.

The Korean alphabet , known as Hangul in South Korea -LRB- also transcribed Hangeul -RRB- and as Chosŏn ` gŭl / Chosŏn Muntcha in North Korea is the alphabet that has been used to write the Korean language since the 15th century . It was created in 1443 under King Sejong the Great during the Joseon Dynasty . Now , the alphabet is the official script of both South Korea and North Korea , and co-official in the Yanbian Korean Autonomous Prefecture and Changbai Korean Autonomous County of China 's Jilin Province . In South Korea , Hangul is used primarily to write the Korean language , as using Hanja -LRB- Chinese characters -RRB- in typical Korean writing had fallen out of common usage during the late 1990s .   In its classical and modern forms , the alphabet has 19 consonant and 21 vowel letters . However , instead of being written sequentially like the letters of the Latin alphabet , Hangul letters are grouped into blocks , such as han , each of which transcribes a syllable . That is , although the syllable han may look like a single character , it is actually composed of three letters : h , a , and n. Each syllabic block consists of two to six letters , including at least one consonant and one vowel . These blocks are then arranged horizontally from left to right or vertically from top to bottom . Each Korean word consists of one or more syllables , hence one or more blocks . The number of mathematically possible distinct blocks is 11,172 , though there are far fewer possible syllables allowed by Korean phonotactics , and not all phonotactically possible syllables occur in actual Korean words . Of the 11,172 possible Hangul syllables , the most frequent 256 have a cumulative frequency of 88.2 % ; with the top 512 , it reaches 99.9 % .