Definition:
pronouns are used as replacements for nouns in a sentence. They can act as the subject, in which case they are used as an alternative to a noun that appears earlier in the sentence or document, or as an object, in which case they are used as an alternative to a noun that appears later in the sentence or document.
Rules and Use:
Themselves should always be used to refer back to a plural noun (e.g. people, children, chickens). It is not used with singular nouns, which should instead use the reflexive pronouns 'himself' and 'herself' when appropriate.
Examples:
1. The children looked in the mirror and smiled at themselves.
2. Sarah and John packed all of their luggage themselves.
3. The players congratulated themselves on a job well done.
Tips:
Be careful not to use 'themselves' in sentences that have singular nouns. Remember to check that the noun the pronoun is referring to is plural. Also note that 'themselves' is always used as a reflexive pronoun, meaning that it is used to refer back to the subject.