這種語言是《魔戒》中的人物實際所說的語言，也是《西境紅皮書》最初編寫用的語言，被稱為Adûni。托爾金解釋：「在這段歷史中由英文所對應的語言是『西方語』，或說是『通用語』。這是在第三紀元的中土世界中通用於西方大地的語言。在這段時間中，它成了居住在雅諾(Arnor)和剛鐸(Gondor)範圍內幾乎所有使用語言種族的母語（只有精靈例外）。這塊區域沿著海岸到昂巴(Umbar)，北到福羅契爾灣(the Bay of Forochel)，內陸直到迷霧山脈(the Misty Mountains)和都阿斯山脈(the Ephel Dúath)。西方語同時也沿著安都因河(Anduin)往北擴散，佔據了河的西岸和東方的山脈，最遠直到格拉頓平原(the Gladden Fields)。（附錄F）」。剛鐸的西方語非常古色古香，而哈比人說的則很質樸。更甚者，那些擁有自己語言的種族也將西方語做為第二語言使用，比如登丹人（沃斯人）和洛汗人。就連半獸人在需要時也會使用簡陋的西方語。在魔多，佛羅多和山姆就能聽得懂要把他們嗅出來的半獸人的對話，因為「他們屬於不同種的半獸人，因此也只能用通用語交談。」（《魔戒三部曲》第六章第二節）。西方語是你進入時光機，回到第三紀元之前的必修課程。（如果你反而去學昆雅語的話，就會像是在去歐洲之前學習拉丁語：沒多少人會懂你在講什麼。）
最初，西方語是「人類專用的語言，不過也曾經在精靈語的影響下變得比較柔和及豐富。它起初是那些被艾爾達族稱做亞塔尼(Atani)或伊甸人(Edain)，『人類始祖』的人類所使用的語言。這其中有三個家族都是精靈之友，他們在第一紀元來到了貝爾蘭。」在第二紀元，努曼諾爾的阿登奈克語，通行於努曼諾爾人在中土世界海岸設立的堡壘和避難所，「而它在混合了許多當地人類的語言之後，就轉化成通用語，通行於所有和這些西方人打交道的區域。」（附錄F）。這個過程在努曼諾爾陸沈之後仍持續著：「伊蘭迪爾的人民並不多，因為只有幾條大船躲過了陸沈和隨之而來的海嘯。他們發現許多西部沿岸居民真的都和他們有同樣的血脈，不管是純正的或是只有一部份，都是努曼諾爾水手和舊時建立的要塞、避難所看守人的後裔；但整體來說，現在登丹人畢竟只是一大群陌生人中的一個小民族罷了。因此，他們用西方語和其他人打交道，並在他們所統治的國家中使用西方語；如此一來，通用語的使用逐漸廣泛，並且……吸收了登丹人的阿登奈克語和諾多林語【辛達語】的詞彙而更加豐富。」（《中土世界民族錄》：33－34）。根據《中土世界民族錄》：315記載，最初的阿登奈克語後來轉變為西方語，部份是因為刻意的忽視：生還的努曼諾爾忠實者對阿登奈克語沒什麼好感，因為這種語言在他們眼裡，代表著叛逆國王們鎮壓其他語言的語言。不過這種語言後來也「在精靈語的影響下變得更柔和。」托爾金將西方與形容為「像現代英語一樣繁雜」（《托爾金書信集》：425）。西方語中的精靈元素大概可以和被轉化成英語的無數個法語單字相比。
We know very little about Westron, for the simple reason that Tolkien has rendered it into English almost everywhere! A few words of genuine Westron are given in Appendix F to LotR and (relatively) many more in The Peoples of Middle-earth. Tolkien even translated the names of the Hobbits. There were never any hobbits called Frodo, Sam, Pippin and Merry; their real names were Maura, Ban, Razar and Kali. The word hobbit itself is just a rendering of the actual Third Age word kuduk (derived from Old English holbytla "hole-dweller" the way kuduk is believed to descend from archaic kûd-dûkan of this meaning, the form kûd-dûkan still being preserved in Rohirric). Maura ("Frodo") and his friends would not have known the word "hobbit" as such; they said kuduk.
Concerning the phonology and structure of Westron, David Salo observes (private communication): "The [consonant] sounds of late Adunaic and Westron are almost the same. They have in common p, b, t, d, k, g, m, n, ng, r, ph, th, s, z, h, y, l. Westron is said in LotR to have the palatals ch, sh, but only sh was exemplified in the material. Westron also has hr-, hl-. No w is exemplified in Westron, but Westron has v, which Adunaic did not. Conceivably Westron could have changed w > v. Westron words are not entirely dissimilar from Adunaic: they have what could be triconsonantal root words (gamba 'he-goat', tapuk 'rabbit', galab 'game', laban 'bag', narag 'dwarf', zilib or zilbi 'butter', and a large number of biconsonantals: rama 'cottager', zara 'old', bana "half", rapha 'burr'."
The vowels constitute a classical five-vowel system: short a, e, i, o, u and long â, î, ô, û; long ê is not attested in any actual word, but its existence is implied by a footnote in Appendix E. (It is there stated that some speakers of Westron used ei and ou, "more or less as in English say no", instead of ê, ô - this pronunciation, though "fairly widespread", was held to be incorrect and rustic. Needless to say, this was the usual pronunciation among the Hobbits.) Reportedly, Westron also had certain reduction vowels.
Westron did not possess the Quenya sounds ty, hy; Gondorian speakers of High-elven substituted ch (as in church) and sh. Neither did Westron have ch as in German ach; see UT:319. Therefore, pure Sindarin Rochand, Rochan became Rohan in Gondorian pronunciation.
One late phonological change is mentioned in PM:320: Double (long) consonants were reduced to single ones medially between vowels, tunnas "guard" being pronounced tunas (but not normally so spelt). Consonants in certain combinations were altered; tunnas itself represents earlier tudnas.
An agental ending -a is seen in such words as pûta "blower", batta "talker". The ending -a was also a masculine ending (PM:46), at least in the Hobbit dialect. Tolkien, when translating the Red Book, Anglicized such names by changing this ending to -o, e.g. "Bilbo" for genuine Hobbitish Bilba. The endings -o and -e were feminine; Tolkien may have substituted -a for -o.
The plural ending seems to be -in, as in cûbuc "hobbit" pl. cûbugin (PM:49 - cûbuc changed to kuduk in the published LotR). Tolkien considered several plural endings before he settled on -in, such as -a, -il, -en. (The idea of unvoiced plosives becoming voiced before this plural ending, as in cûbuc/cûbugin, was apparently dropped later.)
It seems that Westron, like the Scandinavian languages, employs a suffix instead of an independent definite article: Sûza "Shire", Sûzat "The Shire".
The original, archaic Westron seems to have had case endings, but by the end of the Third Age, the endings had been lost. Nargian in Phurunargian "Dwarrowdelf" is a fossilized form of the genitive plural of narag "dwarf". David Salo theorizes: "Since Adunaic has no true genitive, one has to suppose that over the course of the Third Age, Adunaic was transformed (via agglutination of suffixes) into a full-fledged case language, and then subsequently lost case endings again. Nargian could be *nargii (a plural stem, incorporating the old Adunaic ending -i) + an, the old [Adûnaic] 'genitive' marker, now postposed instead of preposed."
The words raza "stranger", razan "foreign" seem to argue the existence of an adjectival ending -n.
The past participle may have the ending -nin; see karnin below.
We know no Westron pronouns, but we know something about them: "The Westron tongue made in the pronouns of the second person (and often also in those of the third) a distinction, independent of number, between 'familiar' and 'deferential' forms. It was, however, one of the peculiarities of Shire-usage that the deferential forms had gone out of colloquial use. They lingered only among the villagers, especially of the West-farthing, who used them as endearments. This was one of the things referred to when people of Gondor spoke of the strangeness of Hobbit-speech. Peregrin Took, for instance, in his first few days in Minas Tirith used the familiar forms to people of all ranks, including the Lord Denethor himself. This may have amused the aged Steward, but it must have astonished his servants. No doubt this free use of the familiar forms helped to spread the popular rumour that Peregrin was a person of very high rank in his own country." (Appendix F) It proved impossible to represent these Westron pronominal distinctions adequately in in Tolkien's English translation of the Red Book.
The strong Elvish influence on Westron is seen even in our small corpus. Some of these words may have been borrowed from Avarin by the ancestors of the Edain, passing into Westron via Adûnaic, some may have been borrowed from Sindarin by the Dúnedain exiles after the Downfall.
(all rejected forms excluded; Tolkien experimented much. Where PM forms disagree with LotR forms, the former are usually silently omitted. Tolkien's spelling is retained throughout, but c and k represent the same sound, k being preferred in LotR - see Tûk).
P.S: In Vinyar Tengwar #32, Carl F. Hostetter and Patrick Wynne argued that whatever the Westron word for garden is, it must begin with a G, just like the English word. This is evident from Galadriel's words to Sam when she gave him a box with a silver rune on the lid before the fellowship left Lórien: "Here is set G for Galadriel, but it may stand for garden in your tongue." Hostetter and Wynne argued that the Westron word for "garden" is ultimately derived from the primitive Elvish stem 3AR (LR:360), which is remarkably similar to the Indo-European stem to which English garden can be traced. "English garden is thus ultimately of Eldarin descent," they conclude. "We can claim that there are indeed 'fairies at the bottom of our garden'."