The reflexive case of they, the third-person singular personal pronoun. The single person previously mentioned, as the object of a verb or following a preposition (also used for emphasis).
The reflexive case of they, the third-person plural personal pronoun. The group of people, animals, or objects previously mentioned, as the object of a verb or following a preposition (also used for emphasis).
You (singular); used emphatically, especially to indicate exclusiveness of the referent's participation in the predicate, i.e., that no one else is involved.
Your own self (singular).