Arabic alphabet

Basic features

The classical Arabic inventory includes twenty-eight primary letters. The script is inherently cursive: most letters connect to adjacent letters and display distinct initial, medial, final and isolated forms. A small group of letters do not join to the following letter, creating visible breaks within words. Common orthographic elements include the hamza (glottal stop), madda (long initial vowel), shadda (consonant doubling) and a set of marks for short vowels and nunation.

Orthography and diacritics

• Short vowels: fatḥa, kasra and ḍamma are written as diacritic marks above or below letters.
• Consonant doubling and absence of vowel: shadda indicates gemination; sukun marks the absence of a vowel.
• Hamza and madda: special signs handle the glottal stop and long initial vowels, with rules that affect writing and pronunciation.
• Definite article and assimilation: orthographic conventions such as the article and the sun–moon letter distinction influence pronunciation and spelling.

Letter joining, ligatures and order

Most letters have up to four contextual forms; a small set of non-joining letters (for example alef, dal, dhal, ra, zay and waw in Arabic) interrupt the cursive flow. Some combinations produce mandatory ligatures in traditional typography, the most common being the lam–alif ligature. Alphabetical order exists in traditional abjad order and in a modern order used for dictionaries and educational materials.

History and calligraphy

The script evolved from earlier Semitic writing systems and the Nabataean script before becoming widely used with the spread of Arabic as a written language. Over centuries it developed a rich calligraphic tradition: early monumental Kufic, the clear and widely used Naskh, the ornamental Thuluth, and the flowing Nastaliq associated with Persian and South Asian literatures. Calligraphic practice shaped letter proportions, ligatures and decorative conventions.

Adaptations to other languages

When adopted for languages such as Persian, Pashto and Urdu, writers added letters and diacritics to represent sounds not present in Arabic. Examples include letters for /p/, /g/ and affricates. The script also appears in other regional contexts and has been used to write a range of minority and regional languages with further modifications.

Modern use, typography and computing

Printing, publishing and digital typography have standardized many letter shapes and introduced fonts suited to display and body text, while preserving calligraphic styles for art and headings. In computing, the Arabic script is encoded in Unicode and supported by modern operating systems and web technologies; open and proprietary fonts implement contextual shaping, ligatures and bidirectional layout required by right-to-left text. Keyboard layouts and input methods vary by language and region.

For introductory overviews and more detailed technical treatments consult general references on scripts, typographic resources and language-specific orthographies. This article provides a concise summary; specialized topics include historical paleography, regional orthographic rules and script pedagogy for non-native learners. See examples of the script in different languages and contexts: Persian, Pashto, Urdu, and broad overviews at general language and script resources: abjad, region, Arabic, Latin comparison, other major scripts.