|Use in other languages|
Kappa (uppercase/lowercase Κ κ), is the letter of the Greek alphabet, used to represent the "k" sound in Ancient and Modern Greek. In the system of Greek numerals, it has a value of 20. Letters that came from it include the Roman K and Cyrillic К.
The letter κ denotes always the sound "k" in Greek. It is customary to transliterate (re-write) κ as "c" in English, but this is somewhat problematic since c is pronounced as "s" before e, i and y, which does not happen in Greek.