Review vs. Revue
Riffle vs. Rifle
Ring vs. Wring
Road vs. Rode
Role vs. Roll
Sensual vs. Sensuous
Serve vs. Service
Set vs. Sit
Shall vs. Will
Shear vs. Sheer
Would vs. Should
Sic vs. Sick
Simple vs. Simplistic
Sole vs. Soul
Stanch vs. Staunch
Stationary vs. Stationery
Stationery vs. Stationer
Statue vs. Statute
Steal vs. Steel
Substitute vs. Substitution