Namely, let's look at the positional adverbs in Spanish (bear with me here).
Aquí: Means "here"; more specifically, right where the speaker is. Let's call this Personal.
Acá: Also means "here"; however, the connotation is more general - it's for stuff that's near you, not stuff that's right where you are. Let's call this Touch (or Melee, if you prefer.)
Ahí: Means "there"; more specifically, it refers to stuff close to the listener, in the room, or to stuff that's near but not here. Let's call this Close.
Allá: Also means "there"; more specifically, it implies stuff that is a middle distance away. Let's call this Medium.
Allí: Another word that means "there"; however, we're talking about stuff that's all the way over there. Let's call this Far Long.
Hey, that's all the standard spell ranges in 3.5! How 'bout that.
