This package defines macros for third-person singular pronouns (\E, \Em, \Eir, \Eirs), which expand differently according to a masculine/feminine switch. (If the switch is masculine, they would expand to he, him, his and his; if feminine, they would expand to she, her, her and hers. Apart from the pronouns, one can define word pairs, such as mother/father, daughter/son, and so on. Gender may be defined once per document, as an environment, or may be flipped on the fly.