Sejong the Great, Hunminjeong'eum - Teaching of the Proper Sounds for the People
“ And therefore, when the unlearned people have a will to speak, it's unavoidable that many of them cannot achieve the intent.予爲此憫然、新制二十八字、欲使人人易習、便於日用耳。I, for the pitiable situation, made twenty-eight new letters, and wish to let everyone easily learn and improve their daily work.ᄀ牙音如君字初發聲、並書如虯字初發聲。ᄀ is a dorsal sound, one which is like the initial sound of the character 君 [1] , and written beside one another, they are like the initial sound of the character 虯 [2] .ᄏ牙音如快字初發聲。ᄏ is a dorsal sound, one which is like the initial sound of the character 快 [3] . ”
