The number of references I’ve come across to ‘twelth’ night recently has prompted me to investigate the spelling of this word. It derives from the Old English word for twelve: twelf, which is a compound of the words ‘two’ and ‘leave’, meaning ‘two left’ (after you’ve taken away ten). Forms of twelve derived in this manner are common to the Germanic languages (compare German zwölf); other Indo-European languages generally employ the formation ‘two’ followed by ‘ten’ (as in Latin duodecem). This is the origin of subsequent ordinal numbers in English: thirteen, fourteen and so on. In Old English twelve was spelled twelfta, from which later spellings such as twelft, twelt and twalt emerged. These forms survived into the seventeenth century in northern dialects and in Scotland, where an alternative spelling twelf is also recorded. Our standard spelling is derived from a southern variant in which the -th ending was added to Old English twelfta by comparison with other ordinal numbers like fourth, fifth, sixth. This form became common in the southern dialects of Middle English, alongside a variant spelling twelth. Twelth continued to appear in printed texts up to the eighteenth century and is found in the works of distinguished writers such as Ben Jonson, showing that our modern misspelling has a long and illustrious pedigree.
Today the spelling twelth is in widespread use online, often on supposedly authoritative sites. It is a common error in references to Shakespeare’s play Twelfth Night: the BBC’s Learning Zone offers clips from an animated version of Twelth Night, while numerous school websites advertise productions with the misspelling. Students researching an essay on the play should be especially wary of sites offering study guides to Twelth Night. Ironically, the spelling adopted for the title of this play in the First Folio edition of 1623 was Twelfe. Such errors would send a shiver down the spines of the librarians responsible for the Typo of the Day website who, paraphrasing Malvolio’s line ‘some have greatness thrust upon them’, warn that ‘a missing “f” ushers no one to greatness’. Not everyone would agree. There is a Facebook group dedicated to changing the spelling of the word twelfth to twelth, on the grounds that most people already spell it that way, and that it is difficult to pronounce the ‘fth’ without spitting. A similar distaste for the word twelfth is encapsulated in the definition offered by Urban Dictionary, which labels it the ugliest word in the English language and urges its readers to avoid it completely: ‘Just don’t say twelfth. It’s disgusting.’