1.PronounThe 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 .
"They’ve hurt themselves.; They fought among themselves.; They are going to try climbing Mount Everest themselves."
2.PronounThe 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 .
"Would whoever stole my phone please make themselves known.; I don't want anyone to fight among themselves.; Everyone must do it themselves."