In my first post about the Hangul writing system, I touched on the history of Hangul and the linguistic motivation for the characters. For example, the Hangul consonant characters were designed to indicate the point of articulation, as shown in the image below (from The World’s Writing Systems):
While I certainly appreciate the linguistic basis for the consonant characters, I find the vowel characters and the mystic symbology of the Korean sound system downright fascinating. The Korean vowel characters combine the core elements for the Earth (ㅡ), the Sun in the Sky (ㆍ), and Man/Human (ㅣ) into sets of dark (or “yin”) vowels and bright (or “yang”) vowels. And the yin and yang must remain in harmony. In bright/yang vowel characters (ㅗ,ㅏ), the Sun in the Sky is above the Earth and to the right of Man (shining in his face). In dark/yin vowel characters (ㅜ,ㅓ), the sun is below the Earth’s horizon or behind Man. Interestingly, it was pointed out to me (thanks Dan!) that in the consonant characters, Man (with his tongue) is facing to the left but in the vowel characters, Man is facing to the right; I am curious about the historical reason for this difference in orientation.
The bright/yang and dark/yin symbology is used consistently in writing the characters for other Korean vowels and diphthongs. For example, yang vowels ㅗ [o] and ㅏ[a] combine to form the diphthong ㅘ [wa], and yin vowels ㅜ [u] andㅓ[ʌ] combine to form ㅝ [wʌ]. In addition, the vowel [i] represented by the Man symbolㅣ is considered neutral (or “mediating”) and can be present with either yin or yang vowels, such as in ㅚ [we] and ㅟ [wi]. But no yin vowel appears in a diphthong character with a yang vowel. (Diphthong, meaning “two sounds,” is a sound composed of two basic vowels; possibly because it is a mouthful to say, diphthong may be the only common modern English word derived from the Ancient Greek root φθόγγος / phthóngos, meaning “sound.”)
The yin and yang harmony can also be seen in the order of vowels in the original Hunminjeongeum document by King Sejong. The vowels are listed first with the three primary elements (Sun/Sky, Earth, Man), then two yang vowels, then two yin, two yang, two yin (the final four are simply the initial 2 yang and 2 yin vowels with an extra Sun/Sky stroke representing an initial iotized [y] sound before the vowel): ㆍ ㅡ ㅣ ㅗ ㅏ ㅜ ㅓ ㅛ ㅑ ㅠ ㅕ
The interesting yin and yang system doesn’t stop with the characters: it also extends to the phonology and morphology of Korean. At the time of the creation of the Hangul system, the Korean language had strong vowel harmony, which favored the construction of words and phrases consisting of vowels that “harmonized” with each other. If a word root had bright/yang vowels, then it would take suffixes containing bright/yang (or neutral) vowels; if the root had yin vowels, it would take yin or neutral suffixes.
Vowel harmony also plays a role in Korean vocabulary that conveys sound symbolism, such as onomatopeia (words imitating actual sounds), phenomimes (words that describe external phenomena), and psychomimes (words that describe psychological states). There are pairs of Korean words, one with yin vowels and one with yang, that have the same (dictionary) definition but that have different connotations. The yang/bright vowel word in the pair typically conveys meanings with smallness or brightness or shallowness. The yin/dark vowel word in contrast conveys depth or size or darkness. For example, there two very similar words for the adjective “red” with very subtle differences in usage. 붉은 (pulgeun) uses the yin/dark vowel ㅜand means a natural red, such as red lips. 빨간 (ppalgan) has the yang/bright vowelㅏand means a brighter, artificial red, such as lips with red lipstick. (For more on this word pair, this video by Ask Hyojin is interesting.) Another example, from the Organic Korean site is the word pair for the sound of falling into water. 퐁당 (pongdang) with the yang/bright vowels is used for small objects (such as stones) falling in water, and 풍덩 (pungdeong) with the yin/dark vowels is used when large objects (such as people) fall into water.
Vowel harmony is weaker in Modern Korean than when Hangul was created, but many remnants of the early harmony live on. The inevitable vowel shift over 650 years has also weakened the connection between King Sejong’s original written vowel system and modern spoken Korean; for example, the original Sun/Sky characterㆍstood for a vowel [ə] that is no longer present in Korean, so the character is no longer used. (The Wikipedia Hangul article contains a lot of interesting details about changes in Hangul since its creation.) Some original diphthongs have also shifted to simple vowels, includingㅐ[ae] from ㅏ + ㅣ, and ㅔ [e] fromㅓ + ㅣ. In addition, the initial Hangul orthography included pitch accents and vowel length markers, both of which have been dropped from Hangul. Nevertheless, despite the underlying language changes over 650 years, the logical design of (and subsequent sensible updates to) the Hangul writing system make it a pleasure to work with as a Korean learner (especially compared to the mess of ambiguity in the English writing system).