no one, but more restricted when referring to common nouns as antecedents, as in "The patient should be told at the outset how much they will be required to pay." "A friend of mine has asked me to go over and help them ..." Use of the pronoun themself is described as being "rare" and "acceptable only to a minority of speakers", while use of the morphologically plural themselves is considered problematic when referring to someone rather than everyone (since only the latter implies a plural set). There are also issues of grammatical acceptability when reflexive pronouns refer to singular noun phrases joined by or, the following all being problematic: "Either the husband or the wife has perjured himself." [ungrammatical] "Either the husband or the wife has perjured themselves." [of questionable grammaticality] "Either the husband or the wife has perjured themself." [typically used by only some speakers of Standard English]. On the motivation for using singular they, A Student's Introduction to English Grammar states: The alternative he or she can be "far too cumbersome", as in: "Everyone agreed that he or she would bring his or her lunch with him or her. or even "flatly ungrammatical", as in "Everyone's here, isn't he or she? "Among younger speakers", use of singular they even with definite noun-phrase antecedents finds increasing acceptance, "sidestepping any presumption about the sex of the person referred to", as in: "You should ask your partner what they think." "The person I was with said they hated the film." Example given by Huddleston et al. Grammatical and logical analysis Notional agreement Notional agreement is the idea that some uses of they might refer to a grammatically singular antecedent seen as semantically plural: Tis meet that some more audience than a mother, since nature makes them partial, should o'erhear the speech." —Shakespeare, Hamlet (1599); quoted in Merriam-Webster's Concise Dictionary of English Usage. "No man goes to battle to be killed." ... "But they do get killed." —George Bernard Shaw, quoted in Merriam-Webster's Concise Dictionary of English Usage According to notional agreement, in the Shakespeare quotation a mother is syntactically singular, but stands for all mothers; and in the Shaw quotation no man is syntactically singular (taking the singular form goes), but is semantically plural (all go [to kill] not to be killed), hence idiomatically requiring they. Such use, which goes back a long way, includes examples where the sex is