There were initially numerous local (epichoric) variants of the Greek alphabet, which differed in the use and non-use of the additional vowel and consonant symbols and several other features. Individual letter shapes were mirrored depending on the writing direction of the current line. The use of both vowels and consonants makes Greek the first alphabet in the narrow sense, as distinguished from the abjads used in Semitic languages, taverna kostas which have letters only for consonants. The period between the use of the two writing systems, Linear B and the Greek alphabet, during which no Greek texts are attested, is known as the Greek Dark Ages. This writing system, unrelated to the Greek alphabet, last appeared in the 13th century BC.
Among consonant letters, all letters that denoted voiced plosive consonants (/b, d, g/) and aspirated plosives (/pʰ, tʰ, kʰ/) in Ancient Greek stand for corresponding fricative sounds in Modern Greek. In both Ancient and Modern Greek, the letters of the Greek alphabet have fairly stable and consistent symbol-to-sound mappings, making pronunciation of words largely predictable. Additionally, Modern and Ancient Greek now use different diacritics, with ancient Greek using the polytonic orthography and modern Greek keeping only the stress accent (acute) and the diaeresis.
- The letter ⟨ε⟩ was called e psilon ("plain e") to distinguish it from the identically pronounced digraph ⟨αι⟩, while, similarly, ⟨υ⟩, which at this time was pronounced y, was called y psilon ("plain y") to distinguish it from the identically pronounced digraph ⟨οι⟩.
- Many symbols have traditional uses, such as lower case epsilon (ε) for an arbitrarily small positive number, lower case pi (π) for the ratio of the circumference of a circle to its diameter, capital sigma (Σ) for summation, and lower case sigma (σ) for standard deviation.
- To write polytonic Greek, one may use combining diacritical marks or the precomposed characters in the "Greek Extended" block (U+1F00 to U+1FFF).
- The form in which classical Greek names are conventionally rendered in English goes back to the way Greek loanwords were incorporated into Latin in antiquity.
- Greek symbols are used as symbols in mathematics, physics and other sciences.
Greek symbols are used as symbols in mathematics, physics and other sciences. In the 9th and 10th centuries, uncial book hands were replaced with a new, more compact writing style, with letter forms partly adapted from the earlier cursive. Such handwriting has been preserved especially from papyrus manuscripts in Egypt since the Hellenistic period. Besides the upright, straight inscriptional forms (capitals) found in stone carvings or incised pottery, more fluent writing styles adapted for handwriting on soft materials were also developed during antiquity. This distinction is an innovation of the modern era, drawing on different lines of development of the letter shapes in earlier handwriting.
Digraphs and letter combinations
For a time, a writing style with alternating right-to-left and left-to-right lines (called boustrophedon, literally 'ox-turning', after the manner of an ox ploughing a field) was common, until in the classical period the left-to-right writing direction became the norm. For a number of letters, sound values differ considerably between Ancient and Modern Greek, because their pronunciation has followed a set of systematic phonological shifts that affected the language in its post-classical stages. The Roman alphabet has a similar extended form with such double-digit letters when necessary, but it is used for columns in a table or chart rather than chapters of an organization. In an organization that expands to more than 24 chapters, the chapter after Ω chapter is AA chapter, followed by AB chapter, etc. As an organization expands, it establishes a B chapter, a Γ chapter, and so on and so forth.
Use for other languages
The letter ⟨ε⟩ was called e psilon ("plain e") to distinguish it from the identically pronounced digraph ⟨αι⟩, while, similarly, ⟨υ⟩, which at this time was pronounced y, was called y psilon ("plain y") to distinguish it from the identically pronounced digraph ⟨οι⟩. Thus, the letters ⟨ο⟩ and ⟨ω⟩, pronounced identically by this time, were called o mikron ("small o") and o mega ("big o"). These four types are often conventionally labelled as "green", "red", "light blue" and "dark blue" types, based on a colour-coded map in a seminal 19th-century work on the topic, Studien zur Geschichte des griechischen Alphabets by Adolf Kirchhoff (1867). When it was adopted for writing Greek, certain consonants were adapted in order to express vowels. During the Mycenaean period, between roughly the 16th and 12th centuries BC, a script called Linear B was used to write the earliest attested form of the Greek language, known as Mycenaean Greek. The form in which classical Greek names are conventionally rendered in English goes back to the way Greek loanwords were incorporated into Latin in antiquity.
By the end of the 4th century BC, it had displaced local alphabets across the Greek-speaking world to become the standard form of the Greek alphabet. Because of Eucleides's role in suggesting the idea to adopt the Ionian alphabet, the standard twenty-four-letter Greek alphabet is sometimes known as the "Eucleidean alphabet". The classical twenty-four-letter alphabet that is now used to represent the Greek language was originally the local alphabet of Ionia. Epichoric alphabets are commonly divided into four major types according to their different treatments of additional consonant letters for the aspirated consonants (/pʰ, kʰ/) and consonant clusters (/ks, ps/) of Greek.
Sound values
In the following group of consonant letters, the older forms of the names in Ancient Greek were spelled with -εῖ, indicating an original pronunciation with -ē. Here too, the changes in the pronunciation of the letter names between Ancient and Modern Greek are regular. In the cases of the three historical sibilant letters below, the correspondence between Phoenician and Ancient Greek is less clear, with apparent mismatches both in letter names and sound values. The name of lambda is attested in early sources as λάβδα besides λάμβδα; in Modern Greek the spelling is often λάμδα, reflecting pronunciation. When the Greeks adopted the Phoenician alphabet, they took over not only the letter shapes and sound values but also the names by which the sequence of the alphabet could be recited and memorized.
Letter shapes
For the range A0–FF (hex), it follows the Unicode range 370–3CF (see below) except that some symbols, like ©, ½, § etc. are used where Unicode has unused locations. Some letters can occur in variant shapes, mostly inherited from medieval minuscule handwriting. Each of these is still a "chapter Letter", albeit a double-digit letter just as 10 through 99 are double-digit numbers.
This system has remained in use in Greek up to the present day, although today it is only employed for limited purposes such as enumerating chapters in a book, similar to the way Roman numerals are used in English. In the classical Ionian system, the first nine letters of the alphabet stood for the numbers from 1 to 9, the next nine letters stood for the multiples of 10, from 10 to 90, and the next nine letters stood for the multiples of 100, from 100 to 900. Several of them denote fricative consonants; the rest stand for variants of vowel sounds. Several Greek letters are used as phonetic symbols in the International Phonetic Alphabet (IPA).