A Dictionary for a Language No One Spoke
In 1447–1448, King Sejong of Joseon oversaw the compilation of the 東國正韻 (Dongguk Jeongun, "Correct Rhymes of the Eastern Kingdom"), a six-volume phonological dictionary prescribing the "correct" Sino-Korean readings of some 91 rhyme categories. The dictionary was technically detailed, but its prescribed readings did not become ordinary Korean usage.
The problem Sejong was trying to solve was real: by the 15th century, Korean readers had been pronouncing Chinese characters in ways that had diverged significantly from contemporary Chinese norms. Each Hanja (Korean term for Chinese characters) had accumulated a Sino-Korean reading (한자음) shaped by centuries of phonological change in Korean, not Chinese. Sejong — the same king who had just created Hangul in 1443 — believed the solution was to reverse-engineer the "authentic" Chinese sounds and impose them on Korean.
An Idealized Chinese as the Gold Standard
The compilers, led by scholar Shin Suk-ju, did not model their pronunciations on contemporary Ming dynasty speech. Instead they worked from the classical rhyme-book tradition — the Yuan 古今韻會擧要 (Gujin Yunhui Juyao, 1297), which Sejong had ordered translated into the new script in 1444, and the Ming 洪武正韻 (Hongwu Zhengyun, 1375), whose title and format the Dongguk Jeongun deliberately echoes. What those books encode is an idealized Middle Chinese — a literary standard, not the living speech of any community. The Dongguk Jeongun layered that theoretical phonology onto Korean phonetics, producing a system doubly removed from spoken reality.
The result was a set of pronunciations that:
- Restored entering-tone (入聲) final stops /-p/, /-t/, /-k/ that had already collapsed in Ming Chinese
- Required ㆆ (a glottal-stop marker) and the ㅭ digraph — Hangul devices that wrote no sound of ordinary Korean
- Imposed syllable-final /-ŋ/ distinctions that Korean speakers did not naturally produce
- Split tonal categories that Korean had merged centuries earlier
Extinct Letters for an Imaginary Sound
The ㆆ and ㅭ letters are perhaps the most haunting legacy of the Dongguk Jeongun. Sejong's Hangul, announced in 1443, was designed with exquisite phonetic precision — each letter's shape supposedly reflecting the position of the speech organs. Yet ㆆ — and the ㅭ digraph the compilers invented to write the entering-tone /-t/ — never stood for a sound of ordinary Korean at all. They were needed only for these artificial readings, and they vanished from use along with them. (ㅸ, by contrast, was a genuine letter of native Korean: it writes everyday words such as 셔ᄫᅳᆯ 'Seoul' and 더ᄫᅥ 'hot' in the Yongbi eocheon ga of 1447, and it died out on its own within a generation.) Modern scholars studying the history of the Hangul alphabet must account for letters that died with the dictionary they were made for.
The Dongguk Jeongun documents an extensive attempt to prescribe Sino-Korean pronunciation. Its rapid abandonment also shows the limits of replacing established spoken forms through a dictionary.
Abandoned but Not Lost
Official use of Dongguk Jeongun pronunciations ceased within two or three generations. By the time of Hunmongjahoe (1527), practical character dictionaries simply recorded the pronunciations Koreans actually used. But the dictionary's failure became linguistics' treasure. Its meticulous Hangul transcriptions preserve a mid-15th century snapshot of how Korean scholars thought Chinese was pronounced, which turns out to be a valuable independent witness to Yuan/early Ming phonology, cross-checkable against Japanese kan-on readings and Vietnamese Hán-Việt pronunciations. The ghosts of ㆆ and ㅭ still haunt phonological reconstructions of Middle Chinese today.