Shillelagh states (emphasis added):
For the Duration, you can use your Spellcasting Ability instead of Strength for the Attack and Damage Rolls of Melee Attacks using that weapon, and the weapon's damage die becomes a d8.
Does this mean you have to use the spellcasting ability, even if Strength is higher? I interpret "can" as giving you the option.
I want to turn a quarter staff's damage die to a d8 while still using strength, on a melee Ranger/Nature Cleric with the polearm master feat.