As more people identify as non-binary, individuals often introduce themselves by the pronouns with which they identify. E-mails are signed with he/him/his, she/her/hers or they/them/theirs. Pronouns are now playing a prominent role in gender politics. This may seem new, but linguists have been puzzling over pronouns for a century or more. Conflicts over pronoun usage goes back to the days of suffrage and gender equality, today it's the usage of a word thought to be plural --"they"--to denote a