Affect or Effect
Loose or Lose
Principle or Principal
Prophecy or Prophesy
Alter or Altar
Adverse or Averse
Break or Brake
Site, Cite or Sight
Peasant or Pheasant
Prey or Pray
Assure, Ensure or Insure
Desert or Dessert
Plane or Plain
Exceed or Accede
Adapt, Adopt or Adept
Storey or Story
Cent, Scent or Sense
Weather or Whether
Economic, Economical or Economics
Conscious or Conscience