A reflexive pronoun is a pronoun which refers back to another pronoun or noun in the same clause. When the subject of the first noun or pronoun, known as the antecedent, is the same as the subject of the second, a reflexive pronoun is appropriate. "Himself" is an example of a reflexive pronoun. This type of pronoun is never the subject of a sentence, other than in archaic or poetic contexts.
English has eight regularly-used reflexive pronouns, although there are a number of rarer forms. In the first person, "myself" is singular while "ourselves" is plural. In the second person, the pronouns are "yourself" and "yourselves." In the third person, "himself," "herself" and "itself" are singular while "themselves" is plural. "Oneself" and "ourself" are rarer, with the latter being used only as a majestic pronoun similar to the "royal we."
A reflexive pronoun occurs when a noun with the same subject has already occurred in the clause. For instance, in the sentence "Gail hummed quietly to herself as she worked," the pronoun stands for "Gail." Since Gail has already appeared as the subject of the sentence, the reflexive pronoun "herself" is appropriate instead of "her."
Usage is identical in sentences where the antecedent is a pronoun rather than a noun. For example, in the sentence "he promised himself this would be his last doughnut of the night," the subject and object of the sentence are the same person, the unnamed "he." As a result, the object of the sentence is the reflexive pronoun "himself."
A reflexive pronoun can also serve to emphasize the subject of a sentence. In this usage, it indicates that the subject, and only the subject, performed the verb of the sentence. For instance, in the sentence "I built the house myself," the use of "myself" indicates that the speaker, and no one else, built the house being discussed.
Not all reflexive pronouns are the object of a sentence. In some cases, they may be the object of a preposition where the object of the verb is something different. For instance, in the sentence "I cooked dinner for myself," "dinner" is the object of the sentence while "myself" is the object of the preposition.
Some speakers misuse the reflexive pronoun by applying it in cases where the subject and object are not the same time. For instance, in the sentence "we sent the letter to yourselves," "yourselves" is used incorrectly. The second pronoun does not refer to the same subject as the first, and therefore "you" is the correct choice. Many people misuse reflexive pronouns in this way, possibly as a result of incorrectly believing that the longer pronoun sounds more sophisticated.