Background

The Korean alphabet and syllables are referred to as Hangul (or Hangeul) in the Republic of Korea (S.), and registered as Jeongeum at ISO. Taylor and Taylor (1983) called Hangul an alphabetic syllabary, because of its dual characteristics of alphabetic script and syllabic script. For example, all of the Hangul syllable blocks (i.e. ‘kulca’ or ‘gulja’ in Korean) should be composed of twenty-four visually distinct letters (fourteen consonants and ten vowels), while Hangul words are usually written and spoken in units of syllable blocks like Hanja (Chinese characters). Before discussing the visual processing of Hangul, we need to understand these dual aspects of Hangul. (Although some terms imply phonemic aspects, this discussion focuses on the visual aspects of Hangul.)

There are fourteen simple Hangul consonant letters including the five visually prototypic consonants (┐, ∟, ⊏, ⋏, and ㅇ) and the others derived from them by adding one to three strokes. These consonant letters can be combined with each other to form another five double consonants and eleven complex consonant letters. The ten simple Hangul vowel letters are derived by combining only three different strokes (·, –, and |). The first of these strokes, the small dot ‘·’, no longer used by itself, is transformed into a short vertical or a short horizontal bar, when added to a long horizontal or a long vertical bar, respectively. These ten simple vowel letters are combined with each other to form eleven compound vowel letters.