Access vs. Excess
Acclimation vs. Acclamation
Acumen vs. Acuity
Ad vs. Add
Adapt vs. Adopt
Adjacent vs. Adjoining
Adopted vs. Adoptive
Adventure vs. Venture
Adverse vs. Averse
Advice vs. Advise
Affect vs. Effect
Affluent vs. Effluent
Affront vs. Effrontery
Afterwards vs. Afterword
Aggravate vs. Irritate
Aid vs. Aide
Aide vs. Aid
Ail vs. Ale
Alighted vs. Lighted
Allergen vs. Allergenic