Invention of Hangeul

Hangeul is the Korean alphabet invented by King Sejong, the 4th King of the Joseon Dynasty (1392~1910). Before Hangeul was invented, people had to learn Hanja (Chinese characters) which was not easy for the common people to learn and use. King Sejong loved his people and sympathized that they could not express their thoughts freely in writing. Thus he decided to create a suitable writing system for expressing the sounds of the Korean language.
With his great effort, "Hunminjeongeum", the book including the newly made Korean alphabet, was published in 1446. "Hunminjeongeum" was the original name of the Korean alphabet as well, which is now called Hangeul.

"Hunminjeongeum" means the correct proper sounds for the instruction of the people. The Hunminjeongeum manuscript was registered as the UNESCO World Documentary Heritage in 1997 and the UNESCO King Sejong Literacy Prize created in 1989 annually pays tribute to those who have made outstanding achievements in promoting literacy. Hangeul is considered to be one of the most efficient alphabets in the world. It is also praised from many language experts for its scientific design. Thus, it has played an important role in developing IT industry in Korea. Koreans celebrate October 9 as Hangeul Day and commemorate the invention of Korean writing system.

Basic Consonants and Vowels of Hangeulul Jamo
There were originally 28 letters when King Sejong first invented Hangeul. But now, there remain 14 consonants and 10 vowels, so only 24 letters are using until present time.
Below are the 24 letters of Korean alphabet.

14 Consonants (Ja Eum)
ㄱ(giyeok) [g,k]	ㄴ(nieun) [n]	ㄷ(digeut) [d,t]	ㄹ(rieul) [r,l]	ㅁ(mieum) [m]
ㅂ(bieup) [b,p]	ㅅ(siot) [s]	ㅇ(ieung) [ng]	ㅈ(jieut) [j]	ㅊ(chieut) [ch]
ㅋ(kieuk) [k]	ㅌ(tieut) [t]	ㅍ(pieup) [p]	ㅎ(hieut) [h]

10 Vowels (Mo Eum)
ㅏ[a]	ㅑ[ya]	ㅓ[eo]	ㅕ[yeo]	ㅗ[o]
ㅛ[yo]	ㅜ[u]	ㅠ[yu]	ㅡ[eu]	ㅣ[i]

Hangeul is a phonetic writing system, which means that we can represent the sounds of Hangeul Jamo (consonants and vowels) in writing. The originality of Hangeul is that it displays the letters in syllabic unit. There are three parts in one syllable. Choseong(the initial), Jungseong(the medial), Jongseong(the final) are them. 19 consonant letters (14 consonants above + ㄲ(ssanggiyeok), ㄸ(ssangdigeut), ㅃ(ssangbieup), ㅆ(ssangsiot), ㅉ(ssangjieut)) can be positioned at Choseong. 'ㅇ' among the consonant letters does not have a sound. 21 vowels(10 vowels above + 11 diphthong; ㅐ,ㅒ,ㅔ,ㅖ,ㅘ,ㅙ,ㅚ,ㅝ,ㅞ,ㅟ,ㅢ) can be located at Jungseong. All the consonant letters except ㄸ, ㅃ, ㅉ and 11 double consonant letters(ㄳ, ㄵ, ㄶ, ㄺ, ㄻ, ㄼ, ㄽ, ㄾ, ㄿ, ㅀ, ㅄ) can be at the Jongseong.

Choseong(the initial)
ㄱ[g,k]	ㄴ[n]	ㄷ[d,t]	ㄹ[r,l]	ㅁ[m]	ㅂ[b,p]	ㅅ[s]
ㅇ[ng]	ㅈ[j]	ㅊ[ch]	ㅋ[k]	ㅌ[t]	ㅍ[p]	ㅎ[h]
ㄲ[k']	ㄸ[t']	ㅃ[p']	ㅆ[s']	ㅉ[c']

Jungseong (the medial)
ㅏ[a]	ㅑ[ya]	ㅓ[eo]	ㅕ[yeo]	ㅗ[o]	ㅛ[yo]	ㅜ[u]
ㅠ[yu]	ㅡ[eu]	ㅣ[i]	ㅐ[ae]	ㅒ[yae]	ㅔ[e]	ㅖ[ye]
ㅘ[wa]	ㅙ[wae]	ㅚ[oe]	ㅝ[wo]	ㅞ[we]	ㅟ[wi]	ㅢ[ui]

Jongseong(the final)
ㄱ[g,k]	ㄴ[n]	ㄷ[d,t]	ㄹ[r,l]	ㅁ[m]	ㅂ[b,p]	ㅅ[s]
ㅇ[ng]	ㅈ[j]	ㅊ[ch]	ㅋ[k]	ㅌ[t]	ㅍ[p]	ㅎ[h]
ㄲ[k']	ㅆ[s']	ㄳ[-k]	ㄵ[-n]	ㄶ[-ㄴ]	ㄺ[-k]	ㄻ[-m]
ㄼ[-l]	ㄽ[-l]	ㄾ[-l]	ㄿ[-p]	ㅀ[-l]	ㅄ[-p]

* For more information
- http://www.prkorea.com/sejong/korean.pdf
 - http://www.prkorea.com/e_learn/e_learn1_1.htm