Locutionary, Illocutionary, Perlocutionary

Would any linguists care to help me understand the difference between the three?

Locution: what someone says (the utterance itself). “He said, ‘ouch’.”

Illocution: the speech act of an utterance. “He complained with a loud ‘ouch’.”
Perlocution: A speech act that has a persuasive motivation. “He said, ‘ouch,’ indicating that he wanted the nurse to remove the needle.”

Ah, so they’re all different *aspects *of the same utterance, not different, mutually-exclusive, *types *of utterances?

I think that’s a good way of putting it.

Check out the branch of linguistics known as pragmatics.