His or her, their
When referring to antecedents of indeterminate gender, we have three options for the possessive adjective: his, his/her (his or her), or their. 1
Until recently his was the most common form; however, it is sometimes considered sexist, so many prefer the neuter form their. Sometimes authors will use her to avoid being sexist or to draw attention to the adjective.
E.g.
Each student must hand over his mobile phone before the exam
Everyone here works at their own pace
The candidate must take his or her own calculator
Every traveller worth her salt has El Camino on her bucket list
Note
Not everyone agrees on what the best option is. The Guardian newspaper, for example, advises against the use of he/his: "Never say 'his' to cover men and women: use his or her, or a different construction; in sentences such as 'a teacher who beats his/her pupils is not fit to do the job', there is usually a way round the problem – in this case, 'teachers who beat their pupils ...' "2
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