Letter

A letter is a written symbol that forms part of an alphabetic system. Letters typically represent a single sound (phoneme) or a group of sounds. When letters are combined in sequence, they form words, and words form sentences.

Letters are distinct from other written symbols such as numerals, punctuation marks (like periods and question marks), and mathematical signs. Some writing systems do not use letters at all, instead employing symbols that represent a single meaningful unit or a whole word.

Alphabets and types of letters

An alphabet is a set of letters arranged in a conventional order. Most alphabets are divided into two types: vowels (sounds in which air flows freely through the mouth, for example a, e, i, o, u) and consonants (sounds in which part of the mouth obstructs the airflow). Many languages have letters in two forms: uppercase (for example A) and lowercase (for example a).

The relationship between letters and sounds

The relationship between letters and sounds is not the same across all languages. In some languages, such as Somali, each letter typically represents a single consistent sound, making the writing straightforward to read. In other languages, such as English, the same letter can represent different sounds depending on the word.

The Somali alphabet

Somali is written using Latin letters, which were officially adopted in 1972. The system uses most Latin letters, with C, X, and Q assigned to sounds specific to Somali. The letters P, V, and Z are not normally used in native words. Vowel length is marked by writing the vowel letter twice, for example 'aa' and 'oo'.