The only two-letter word beginning with "c" in the English language is "ca'," according to Merriam Webster. The word ca' is the Scottish variant of the word call.
In the English language, ca' is a verb that means "to call," such as "to urge someone forward by calling," according to Dictionary.com. But other than ca,' there are no two-letter words that begin with the letter "c." There are, however, numerous two-letter acronyms that begin with "c" as well as many prefixes that begin with "c." For instance, the prefix "co" means "joint, mutual or common," according to Merriam Webster. An example of a word with the prefix "co" is "co-education."
Ci is an abbreviation for "cirrus" and "curie." It is also an acronym for collective intelligence, calorie intake, configuration item and confidence interval, among others. Cu is the symbol for copper on the periodic table of elements and is also the abbreviation for cumulus and cubic. Ce is the symbol for cerium on the periodic table of elements, and it's also the abbreviation for chemical engineer, chief engineer, common era, civil engineer and church of England, explains Dictionary.com. Cy is an abbreviation for calendar year, cyprus, cubic yard and church youth, according to Abbreviations.com.