Which word would not be synonymous with "your"?

The word "yourself" is accurately identified as not being synonymous with "your." "Your" is a possessive pronoun used to indicate ownership or belonging to the person being addressed. In contrast, "yourself" is a reflexive pronoun that refers back to the subject of the sentence, usually the same individual to whom "your" refers, and it can imply actions directed at that same person.

For example, in the sentence "You should take care of yourself," "yourself" emphasizes the individual who is being instructed. Therefore, while it relates to the same person addressed by "your," it serves a different grammatical function.

The other words—"their," "our," and "my"—are all forms of possessive pronouns that express ownership or association, thus making them synonymous with "your," as they indicate possession in relation to the noun they modify.