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 Ϙ 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.[2]
The Etruscans used Q in conjunction with V to represent /k
