The Letter C has a busy place in the English alphabet. Its sound may be
... a hard C, as in CAPITAL
... a soft C, as in OCEAN
... combined with an H (borrowed from the French), as in CHAMPAGNE
... changed for a British word - as in CURB (not kerb),or be silent, as in MUSCLE.
A little history… David Sacks tells us in his book Letter Perfect, “Back in 1000 BC, the third letter of the Phoenician alphabet was the letter G, gimel. It came after B and before D.” The Greeks copied this alphabet around 800 BC, but the letter C had not appeared yet. In the B.C. 700s, the Etruscans (who lived in Italy and were trading partners with the Greek) changed the gimel to gamma. They also changed the letter to a hard C sound, as in kay. And it stuck.
When Latin was written in the B.C. 600s, the Romans gave the Letter G its own place in their alphabet, and kept the Letter C in the third place. It was used, for example, in the name for Cupid. The soft C sound began to be used by the common people. After Rome's fall in around A.D.500: “the slurred C became part of the Romance languages… which arose from dying Latin.”
Middle English, a combination of French and Old English came to England after the Norman Invasion in 1066 AD. It looks to me that many French words joined the English language at that time.
To learn more about the letters in the English language, try David Sacks’ book, Letter Perfect. And read more AlphabeThursday posts that begin with the Letter C, over at Ms. Jenny’s site, …off on my tangent…