A Latin-script alphabet (Latin alphabet or Roman alphabet) is an

alphabet An alphabet is a standardized set of basic written graphemes (called letters) that represent the phonemes of certain spoken languages. Not all writing systems represent language in this way; in a syllabary, each character represents a syllab ...

that uses

letters Letter, letters, or literature may refer to: Characters typeface * Letter (alphabet), a character representing one or more of the sounds used in speech; any of the symbols of an alphabet. * Letterform, the graphic form of a letter of the alpha ...

of the

Latin script The Latin script, also known as Roman script, is an alphabetic writing system based on the letters of the classical Latin alphabet, derived from a form of the Greek alphabet which was in use in the ancient Greek city of Cumae, in southern ...

. The 21-letter archaic Latin alphabet and the 23-letter

classical Latin alphabet The Latin alphabet or Roman alphabet is the collection of letters originally used by the ancient Romans to write the Latin language. Largely unaltered with the exception of extensions (such as diacritics), it used to write English and the ...

belong to the oldest of this group. The 26-letter modern

Latin alphabet The Latin alphabet or Roman alphabet is the collection of letters originally used by the ancient Romans to write the Latin language. Largely unaltered with the exception of extensions (such as diacritics), it used to write English and the ...

is the newest of this group.

Encoding

The 26-letter

ISO basic Latin alphabet The ISO basic Latin alphabet is an international standard (beginning with ISO/IEC 646) for a Latin-script alphabet that consists of two sets ( uppercase and lowercase) of 26 letters, codified in various national and international standards and ...

(adopted from the earlier

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...

) contains the 26 letters of the

English alphabet The alphabet for Modern English is a Latin-script alphabet consisting of 26 letters, each having an upper- and lower-case form. The word ''alphabet'' is a compound of the first two letters of the Greek alphabet, ''alpha'' and '' beta''. ...

. To handle the many other alphabets also derived from the classical Latin one, ISO and other telecommunications groups "extended" the ISO basic Latin multiple times in the late 20th century. More recent international standards (e.g. Unicode) include those that achieved ISO adoption.

Key types of differences

Apart from alphabets for modern spoken languages, there exist phonetic alphabets and

spelling alphabet A spelling alphabet ( also called by various other names) is a set of words used to represent the letters of an alphabet in oral communication, especially over a two-way radio or telephone. The words chosen to represent the letters sound sufficien ...

s in use derived from Latin script letters. Historical languages may also have used (or are now studied using) alphabets that are derived but still distinct from those of classical Latin and their modern forms (if any). The Latin script was typically slightly altered to function as an alphabet for each different language (or other use), although the main letters are largely the same. A few general classes of alteration cover many particular cases: *

diacritic A diacritic (also diacritical mark, diacritical point, diacritical sign, or accent) is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek (, "distinguishing"), from (, "to distinguish"). The word ''diacrit ...

s could be added to existing letters; * two letters could be fused together into ligatures; * additional letters could be inserted; or * pairs or triplets of letters could be treated as units ( digraphs and trigraphs). These often were given a place in the alphabet by defining an alphabetical order or collation sequence, which can vary between languages. Some of the results, especially from just adding diacritics, were not considered distinct letters for this purpose; for example, the French é and the German ö are not listed separately in their respective alphabet sequences. With some alphabets, some altered letters are considered distinct while others are not; for instance, in Spanish, ñ (which indicates a unique phoneme) is listed separately, while á, é, í, ó, ú, and ü (which do not; the first five of these indicate a nonstandard stress-accent placement, while the last forces the pronunciation of a normally-silent letter) are not. Digraphs in some languages may be separately included in the collation sequence (e.g. Hungarian CS, Welsh RH). New letters must be separately included unless collation is not practised.

Properties

Letter inventory

Coverage of the letters of the

can be * complete * partial and additional letters can be * absent * present, either as ** letters with diacritics (e.g. in the Danish, Norwegian and Swedish alphabets) ** new letter forms (e.g. in

Azerbaijani alphabet The Azerbaijani alphabet ( az, Azərbaycan əlifbası, , ) has three versions which includes the Perso-Arabic, Latin, and Cyrillic alphabets. North Azerbaijani, the official language of Republic of Azerbaijan, is written in a modified Latin a ...

)

Grapheme order

Most alphabets have the letters of the ISO basic Latin alphabet in the same order as that alphabet.

Multigraphs

Some alphabets regard digraphs as distinct letters, e.g. the old

Spanish alphabet Spanish orthography is the orthography used in the Spanish language. The alphabet uses the Latin script. The spelling is fairly phonemic, especially in comparison to more opaque orthographies like English, having a relatively consistent mappin ...

had CH and LL sorted apart from C and L. Some Spanish dictionaries still list "ll" separately.

Diacritics

Some alphabets sort letters that have diacritics at the end of the alphabet. Examples are the Scandinavian Danish, Swedish, Norwegian, and Finnish alphabets.

New letter forms

Icelandic sorts some additional letters at the end, as well as one letter with diacritic, while others with diacritics are sorted behind the corresponding non-diacritic letter.

Grapheme–sound correspondence