In the third person,-self or-selves is attached to the pronoun's objective form (him,them); in the first person and second person, to its prenominal possessive form (my,your).
The suffixes-self and-selves may be separated by an intervening word or phrase (especiallyown) from the rest of the pronoun. When this occurs,self orselves stands alone as its own word, and the pronoun's prenominal possessive form is necessarily used; hence "himself" becomes "his own self", not *"him own self".
The use of "themself" instead of "themselves" is sometimes proscribed, but it follows the contrast with "yourselves" and "yourself" and "ourselves" and "ourself".
These forms are sometimes used in formal contexts in place of the objective personal pronoun: "the quality of service you have received from ourselves" (us). This usage is often criticized.
