Pronouns, especially the “self” ones that end in “self” or “selves,” are tricky.
Many speakers and writers use them everywhere, but these pronouns have a very limited grammatical purpose: They’re meant to be mirror image of the subject of the sentence or clause they’re in. And that’s it. Nothing else.
Self pronouns may only be used when they refer back to a previously mentioned noun, the subject of a sentence or clause, who MUST be the same person. It’s like looking in a mirror: The pronoun has to reflect the image of the original subject.
These pronouns are called reflexive pronouns when they’re used this way; they’re also called intensive or emphatic pronouns with a slightly different usage (see examples way down below), but they still follow the basic rule.
Used as a reflexive pronoun:
YES: I sang to myself while I was cooking. (I and myself are the same person.)
NO: John sang to myself while we were cooking. (John and myself are NOT the same person.)
YES: John sang to me while we were cooking.
YES: John sang to himself while we were cooking. (John and himself are the same person.)
YES: John sang to him while we were cooking. (John sang to another male, not himself.)
YES: As I was cooking dinner, John quietly sang to himself.
YES: As I was cooking dinner, John quietly sang to him (another male).
Used as an intensive (emphatic) pronoun:
YES: I myself heard John say that! (Again, I and myself are the same person.)
YES: Sara herself created that post this morning on using I and myself.
Oh, and the self pronoun can never, never, EVER be the first word or the subject in a sentence.
NO: Myself and John …
NO: John and myself …
YES: John and I …
BONUS: These words do NOT exist (even most spellcheck programs know this): hisself, ourself, ourselfs, theirself, theirselfs, themself, themselfs, her’s, him’s, his’s, our’s, their’s, your’s.
But you know what? The LI spellcheck accepted the last six that I just wrote! Yikes. I wouldn’t have thought it possible. I need to send someone at LI a note. I promise you that they are not real words.
The basic premise here is that the self pronouns cannot be used unless they refer to (reflect back to) the subject of the sentence or clause they’re in.
I hope this helps, and if you have any questions, please ask!