a top hook
in most fonts
small Latin alpha
a top hook
small script "G"
in some fonts
small long "S"
In graphemics, the term allograph denotes any glyphs that are considered variants of a letter or other grapheme, like a number or punctuation. An obvious example in English (and many other writing systems) is the distinction between uppercase and lowercase letters. Allographs can vary vastly, without affecting the underlying identity of the grapheme. Even if the word "cat" is rendered as "cAt", it remains recognizable as the sequence of the three graphemes
Letters and other graphemes can also have huge variations that may be missed by many readers. The letter g, for example, has two common forms (glyphs) in different typefaces, and an enormous variety in people's handwriting. A positional example of allography is the so-called long s, a symbol which was once a widely used non-final allograph of the lowercase letter s. A grapheme variant can acquire a separate meaning in a specialized writing system. Several such variants have distinct code points in Unicode and so ceased to be allographs for some applications.
The fact that handwritten allographs differ so widely from person to person, and even from day to day with the same person, means that handwriting recognition software is enormously complicated.
In the Chinese script, there exist several graphemes that have more than one written representation. Chinese typefaces often contain many variants of some graphemes. Different regional standards have adopted certain character variants. For instance:
An allograph may also be a smaller fragment of writing, that is a letter or a group of letters, which represents a particular sound. In the words cat and king, the letters c and k are both allographs of the same sound. This relationship between a letter and a sound is not necessarily fixed, for example in a different word, such as city, c is instead an allograph of an s sound.
Some words use groups of letters to represent a sound. In kick both k and ck are allographs of the sound that the c in cat represents. These associations are learned as part of learning to read and write a language. However, the development of phonetic associations is more difficult when deaf children are learning written languages. For example, without auditory knowledge of words, children are unable to associate graphemes with phonemes, or the sounds of letters or groups of letters. This lack of alphabetic knowledge correlates with delayed literacy in early learning.
|cat, mecca, chemistry, back, lacquer, biscuit, sgraffito, key, khan, dekko, walk, Qatar, bouquet||Complicated allographs may surprise or baffle language learners, just as those in place names can continue to confuse people who are unfamiliar with a particular location, even when they are native speakers of the language. One notorious allograph in the English language is ough, which may easily represent more than 10 different sounds, depending on the word in which it is used.|
The primary reason that we accept all these varieties as representing the same sound or grapheme is that we have been taught to make these associations when learning to read the English language. That is to say, their meaning and correspondence is assigned arbitrarily, by conventions adopted and observed by a particular language community. Many of these associations have to be unlearned if we study a second language whose writing system is based upon, or contains many elements similar to or shared by, our own alphabet or writing system. Very often, the letters one might be comfortable and familiar with are allographs of quite different sounds in the second language. For example, in written Spanish the grapheme ?v? will often represent the phoneme /b/, whereas in English this does not occur.
The term 'allograph' is used to describe the different representations of the same grapheme or character in different typefaces. The resulting font elements may look quite different in shape and style from the reference character or each other, but nevertheless their meaning remains the same. In Unicode, a given character is allocated a code point: all allographs of that character have the same code point and thus the essential meaning is retained irrespective of font choice at time of printing or display.
In Arabic the abstract, nominal graphemes are represented by context-dependent allographs. Simplified support for Arabic handles contextual allographs according to two patterns, discontinuous and continuous assimilation. (Allographs and Ligatures)