Comprehensive vs. Comprehensible
Concave vs. Convex
Confidant vs. Confident
Congenital vs. Congenial
Conscious vs. Conscience
Subsequently vs. Consequently
Console vs. Condole
Consul vs. Council
Contemporaneous vs. Contemporary
Contemptible vs. Contemptuous
Continual vs. Continuous
Continuance vs. Continuation
Converge vs. Diverge
Corpse vs. Corps
Councilor vs. Counselor
Crass vs. Cross
Credibility vs. Credence
Credible vs. Creditable
Criterion vs. Criteria
Currant vs. Current