Cannot for Can. "I cannot but go." Say, I can but go.
Capable. "Men are capable of being flattered." Say, susceptible to flattery. "Capable of being refuted." Vulnerable to refutation. Unlike capacity, capability is not passive, but active. We are capable of doing, not of having something done to us.
Capacity for Ability. "A great capacity for work." Capacity is receptive; ability, potential. A sponge has capacity for water; the hand, ability to squeeze it out.
Casket for Coffin. A needless euphemism affected by undertakers.
Casualties for Losses in Battle. The essence of casualty is accident, absence of design. Death and wounds in battle are produced otherwise, are expectable and expected, and, by the enemy, intentional.
Chance for Opportunity. "He had a good chance to succeed."
Chin Whiskers. The whisker grows on the cheek, not the chin.
Chivalrous. The word is popularly used in the Southern States only, and commonly has reference to men's manner toward women. Archaic, stilted and fantastic.
Citizen for Civilian. A soldier may be a citizen, but is not a civilian.
Claim for Affirm. "I claim that he is elected." To claim is to assert ownership.