Orthography

The conventional spelling system of a language, including the rules and patterns that govern how sounds (phonemes) are represented by written symbols (graphemes). Languages vary in orthographic depth: shallow or transparent orthographies like Spanish and Italian have consistent letter-to-sound correspondences, while deep or opaque orthographies like English have many irregular spellings. Orthographic depth significantly affects how dyslexia manifests — in shallow orthographies, reading speed is the primary indicator of difficulty, whereas in deep orthographies, both accuracy and speed are affected. Understanding orthographic systems is important for designing accessible text content and multilingual reading tools.