Q is the seventeenth letter of the modern Latin alphabet. Its name in English ( ) is spelled cue.

The Semitic sound value of Qôp (perhaps originally qaw, "cord of wool", and possibly based on an Egyptian hieroglyph) was /q/ (voiceless uvular plosive), a sound common to Semitic languages, but not found in English or most Indo-European ones. In Greek, this sign as Qoppa probably came to represent several labialized velar plosives, among them /kʷ/ and /kʷʰ/. As a result of later sound shifts, these sounds in Greek changed to /p/ and /pʰ/ respectively. Therefore, Qoppa was transformed into two letters: Qoppa, which stood for a number only, and Phi Φ which stood for the aspirated sound /pʰ/ that came to be pronounced /f/ in Modern Greek.

In the earliest Latin inscriptions, the letters C, K and Q were all used to represent the sounds /k/ and /g/ (which were not differentiated in writing). Of these, Q was used to represent /k/ or /g/ before a rounded vowel (e.g. "EQO" = ego), K before /a/, and C elsewhere. Later, the use of C (and its variant G) replaced most usages of K and Q: Q survived only to represent /k/ when immediately followed by a /w/ sound.

The Etruscans used Q only in conjunction with V to represent /kʷ/Fact: date=February 2009.

Usage

In most modern western languages written in Latin script, such as in Romance and Germanic languages, Q appears almost exclusively in the digraph QU, though see Q without U. In English this digraph most often denotes the cluster /kw/, except in borrowings from French where it represents /k/ as in plaque. In Italian qu represents /kw/ (where /w/ is the semivowel allophone of /u/); in German, /kv/; and in French, Occitan, Catalan, Spanish and Portuguese, /k/ or /kw/; in the same languages qu replaces c for /k/ before front vowels i and e, since in those contexts c is a fricative and letter 'k' is seldom used outside loan words.) Danish abolished the letter in 1872, although it's still part of the alphabet. A consequence of this was the change in spelling of the word 'kvinde' (woman), which prior to 1872 was spelt 'Quinde'. As a result the term 'kvinde med q' (woman spelt with q) is used for an old-fashioned woman, whilst 'kvinde med k' is used about a modern woman.

In the Aymara, Aleut, Yup'ik, Inuit, Greenlandic, Uzbek, Quechua, and Tatar languages, as well as romanised Arabic, Q is a voiceless uvular plosive. 1 is also used in the IPA for the voiceless uvular plosive, as well as in most transliteration schemes of Semitic languages for the "emphatic" qōp sound. The sound is rendered with letter ﻕ in Arabic script.

In Maltese and Võro, Q denotes the glottal stop.

In Albanian, q represents the voiceless palatal plosive, /c/. In Chinese Hanyu Pinyin, Q is used to represent the sound 2, which is close to English "ch" in "cheese".