In the linguistic study of written languages, a syllabary is a set of written symbols that represent the syllables or (more frequently) moras which make up words. A symbol in a syllabary, called a syllabogram, typically represents an (optional) consonant sound (simple onset) followed by a vowel sound (nucleus)—that is, a CV or V syllable—but other phonographic mappings, such as CVC, CV- tone, and C (normally nasals at the end of syllables), are also found in syllabaries. Types A writing system using a syllabary is complete when it covers all syllables in the corresponding spoken language without requiring complex orthographic / graphemic rules, like implicit codas ( ⇒ /C1VC2/) silent vowels ( ⇒ /C1V1C2/) or echo vowels ( ⇒ /C1V1C2/). This loosely corresponds to shallow orthographies in alphabetic writing systems. True syllabograms are those that encompass all parts of a syllable, i.e. initial onset, medial nucleus and final coda, but since onset and coda are optional in at least some languages, there are middle (nucleus), start (onset-nucleus), end (nucleus-coda) and full (onset-nucleus-coda) true syllabograms. Most syllabaries only feature one or two kinds of syllabograms and form other syllables by graphemic rules. Syllabograms, hence syllabaries, are pure, analytic or arbitrary if they do not share graphic similarities that correspond to phonic similarities, e.g. the symbol for ka does not resemble in any predictable way the symbol for ki, nor the symbol for a. Otherwise they are synthetic, if they vary by onset, rime, nucleus or coda, or systematic, if they vary by all of them. Some scholars, e.g. Daniels, reserve the general term for analytic syllabaries and invent other terms (abugida, abjad) as necessary. Some systems provide katakana language conversion. Languages using syllabaries Languages that use syllabic writing include Japanese, Cherokee, Vai, the Yi languages of eastern Asia, the English-based creole language Ndyuka, Xiangnan Tuhua, and the ancient language Mycenaean Greek (Linear B). In addition, the undecoded Cretan Linear A is also believed by some to be a syllabic script, though this is not proven. Chinese characters, the cuneiform script used for Sumerian, Akkadian and other languages, and the former Maya script are largely syllabic in nature, although based on logograms. They are therefore sometimes referred to as logosyllabic. The contemporary Japanese language uses two syllabaries together called kana (in addition to the non-syllabic systems kanji and romaji), namely hiragana and katakana, which were developed around 700. Because Japanese uses mainly