Allographs

Allographs are the variant shapes used to write the same letter, grapheme, or phoneme in a writing system. The term is used in linguistics, paleography, and typography to describe how a single underlying symbol can appear in different glyph forms across fonts, handwriting, or languages.

In linguistics, allographs refer to alternative spellings that represent the same phoneme. A single sound may be written with different letters or letter combinations in different words or languages. For example, the English phoneme /f/ can be written as f as in fun, as ph in borrowed words such as phone, or as ff in some older spellings; all of these are written representations of the same sound, though some are digraphs rather than a single letter.

Another well-known example is the long s (ſ) used in early modern typography for the letter s, which is an allograph of s used in the same word; modern type uses the short s form instead. In typography, changing fonts can produce different letter shapes that still represent the same grapheme, such as the same a or g appearing in various forms.

Allographs are distinct from allomorphs, which are variants of a morpheme’s pronunciation rather than its written form. The study of allographs helps paleographers interpret historical texts and assists typographers and spell-checkers in handling orthographic variation.

In digital text processing, recognizing allographs can matter for OCR and search, as different glyph shapes may correspond to the same underlying symbol. Understanding allographs also illuminates how writing systems map sounds to symbols and how orthography evolves over time.