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Yes, from the OED blog: The Oxford English Dictionary traces singular they back to 1375, where it appears in the medieval romance William and the Werewolf. Except for the old-style language of that poem, its use of singular they to refer to an unnamed person seems very modern. Here’s the Middle English version: ‘Hastely hiȝed eche . . . þei neyȝþed so ...


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The question could be answered by comparison of the King James Bible (1611 version) with the Wycliffe Bible (1382) but would require some considerable research. Here are two examples I found myself, which indicate that 'they/their/them' was not used singularly prior to the 16th century : 2 Kings 14:12 : 1611 every man to their tents 1382 ech man in to his ...


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