In English, prepositions are short words like “from” or “to” used to construct small phrases expressing some relationship to other elements in the sentence. The name of this grammatical function is biased towards its use in European languages, where such elements usually appear at the beginning of the phrase. In Adûnaic, the “prepositions” are instead expressed as suffixes added to the end of the word (SD/435):

• nardûn nakkha kadarô “the soldier came from the city”
• Ar-Pharazônun yadda Arminalêthada “Ar-Pharazon went to Armenelos”.

The noun modified by the prepositional suffix is always in the normal case (SD/429). Furthermore, if the noun ends in -u or -i and the prepositional suffix begins in a vowel, the usual glide-consonant w or y is inserted between the two vowels:

• Ar-Pharazônun azaggara Avalôiyada (Avalôi-y-ada) “Ar-Pharazôn was warring against the Powers” (SD/247)
• Bârim an-Adûn yurahtam dâira sâibêth-mâ Êruvô (Êru-w-ô) “Lords of the West, they broke the Earth with assent from Eru” (SD/247)

In the second example, the letter “v” is properly pronounced [w] when Adûnaic is represented with English letters (SD/434). Although not discussed by Tolkien, other vowel combinations in prepositions probably follow the usual rules for Adûnaic vowel-combinations.

The known prepositional suffixes appearing in the Lament of Akallabêth (SD/247) and “Lowdham’s Report on the Adunaic Language” (SD/429) from the 1940s are:

• -ada “to, towards”
• -dalad “under, beneath”
• -mâ “with”
• -nud “on”
• -ô “from”
• -zê “at”
• -ak “away” [speculative]

A few more prepositional elements appear in Tolkien’s later writings (PM/376), but these were used as prefixes:

• nad “behind”
• ob “before”

Draft Adûnaic: In Tolkien’s early Adûnaic drafts, most these prepositional suffixes were instead examples of the draft-cases, with further modifications for the number and gender of the noun. In later Adûnaic grammar, Tolkien abandoned this case syntax and switched to simple, immutable prepositional suffixes, as discussed above.