Westron, Adûni, or Sôval Phârë, is the constructed language that was supposedly the Common Speech used in J. R. R. Tolkien's world of Middle-earth in the Third Age, at the time of The Lord of the Rings. It supposedly developed from Adûnaic, the ancient language of Númenor. In practice in the novel, Westron is nearly always represented by modern English, in a process of pseudo-translation which also sees Rohirric represented by Old English. That process allowed Tolkien not to develop Westron or Rohirric in any detail. In the Appendices of the novel, Tolkien gives some examples of Westron words.

When writing The Lord of the Rings (1954–55), a sequel to The Hobbit (1937), Tolkien came up with the literary device of using real languages to "translate" fictional languages. He pretended that he had not composed the book himself but translated it from Westron (named Adûni in Westron) or Common Speech (Sôval Phârë, in Westron) into English. The purpose of this was to provide an explanation for why the Common Speech is almost entirely rendered as English in the novel. This device of rendering an imaginary language with a real one was carried further by rendering:^[1]

• Rohirric, the language of Rohan (related to Westron) by the Mercian dialect of Old English^[1]
• names in the tongue of Dale by Old Norse forms^[1]
• names of the Kingdom of Rhovanion by Gothic forms, thus mapping the genetic relation of his fictional languages on to the existing historical relations of the Germanic languages.^[1]

The whole device of linguistic mapping was essentially a fix for the problems Tolkien had created for himself by using real Norse names for the Dwarves in The Hobbit, rather than inventing new names in Khuzdul. This seemed a clever solution, as it allowed him to explain the book's use of Modern English as representing Westron.^[2] Because of this, Tolkien did not need to work out the details of Westron grammar or vocabulary in any detail.^[3]

Tolkien went further, using Gothic names for the early leaders of the Northmen of Rhovanion, ancestors of Rohan, and for the first Kings of Rohan.^{[T 2][4]} Gothic was an East Germanic language, and as such is a forerunner of Old English, not a direct ancestor.^[5] Christopher Tolkien suggests that his father intended the correspondence between the language families to extend back to the ancestral language of the Northmen.^{[T 2]}

Westron (also called Adûni) supposedly developed from Adûnaic, the ancient language of Númenor.^{[T 4]} It became the lingua franca for all the peoples of Middle-earth:^[6] Tolkien gives some examples of Westron words in Appendix F to The Lord of the Rings, where he summarizes Westron's origin and role as lingua franca in Middle-earth:^{[T 5]}

The language represented in this history by English was the Westron or 'Common Speech' of the West-lands of Middle-earth in the Third Age. In the course of that age it had become the native language of nearly all the speaking-peoples (save the Elves) who dwelt within the bounds of the old kingdoms of Arnor and Gondor ... At the time of the War of the Ring at the end of the age these were still its bounds as a native tongue.^{[T 5]}

He explains further that

the Númenóreans had maintained ... havens upon the western coasts of Middle-earth for the help of their ships; and one of the chief of these was at Pelargir near the Mouths of Anduin. There Adûnaic was spoken, and mingled with many words of the languages of lesser men it became a Common Speech that spread thence along the coasts among all that had dealings with Westernesse.^{[T 5]}

Tolkien gives a few names in Westron, saying that Karningul was the translation of Elvish Imladris, Rivendell, while Sûza was Westron for the Shire. Hobbit surnames Took and Boffin were "anglicize[d]" from Westron Tûk and Bophîn. The original form of Brandybuck was Zaragamba, "Oldbuck", from Westron zara, "old", and gamba, "buck".^{[T 5]} He explains, too, that Sam[wise] and Ham[fast] "were really called Ban and Ran", shortened from Westron Banazîr and Ranugad.^{[T 5]} Tolkien states that these had been nicknames, meaning "halfwise, simple" and "stay-at-home", which he had chosen to render by English names, from Old English samwís and hámfoest with equivalent meanings.^{[T 5]} Nick Groom states that Sûza, Banazîr, and the Westron for Sam's surname "Gamgee", Galbasi, are all derived from Gothic, a precursor of Old English, adding yet another layer of linguistic complexity to the pseudotranslation.^[7]

The word Hobbit, which the narrator admits "is an invention", could, he explains, easily be a much-worn form of the Old English holbytla, "hole-dweller". This corresponds to the Westron dialect form kuduk, used in Bree and the Shire, which the narrator supposes was probably a worn form of the word kûd-dûkan, of the same meaning, stating that Merry had heard King Théoden of Rohan use this name for Hobbit.^{[T 5]}

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