One of the languages of Arda in Tolkien's Middle-earth legendarium, Adûnaic was spoken by the Men of Númenor during the Second Age.
[3] Tolkien devised Adûnaic (or Númenórean), the language spoken in Númenor, shortly after World War II, and thus at about the time he completed The Lord of the Rings, but before he wrote the linguistic background information of the Appendices.
It is there that the most extensive sample of the language is found, revealed to one of the (modern-day) protagonists, Lowdham, in a visionary dream of Atlantis.
[6] The phonology is as follows:[4] 1Adûnaic is fundamentally a three-vowel language, with a length distinction; the long eː and oː are derived from diphthongs aj and aw, as is the case in Hebrew and in most Arabic dialects, in line with the Semitic flavour that Tolkien intended for both Adûnaic and Khuzdul, which influenced it.
[4] Example declensions: This Adûnaic text, part of the tale of the Fall of Númenor, appears in The Notion Club Papers.
It is fragmentary because it appeared in a dream to Tolkien's frame story character Lowdham, and is only partially translated by him because he did not know the language.
[4] Kadōand sozigūrunSauronzabathānhumbledunakkhahe-came......ēruhīnimChildren of GodKadō zigūrun zabathān unakkha ... ēruhīnim{and so} Sauron humbled he-came ... {Children of God}dubdamfellugru-daladshadow-under......ar-pharazōnunAr-Pharazonazaggarawas warringdubdam ugru-dalad ... ar-pharazōnun azaggarafell shadow-under ... Ar-Pharazon {was warring}avalōiyadaagainst Powers......bārimLordsan-adūnof-WestyurahtambrokedāiraEarthavalōiyada ... bārim an-adūn yurahtam dāira{against Powers} ... Lords of-West broke Earthsāibēth-māassent-withēruvōGod-from......azrīyaseasdu-phursāso-as-to-gushakhāsadainto chasmsāibēth-mā ēruvō ... azrīya du-phursā akhāsadaassent-with God-from ... seas so-as-to-gush {into chasm}......anadūnēNumenorzīrānbelovedhikallabashe-fell down......bawībawindsdulgīblack... anadūnē zīrān hikallaba ... bawība dulgī... Numenor beloved {she-fell down} ... winds black......balīkshipshazadsevenan-nimruzīrof-Elendilazūladaeastward... balīk hazad an-nimruzīr azūlada... ships seven of-Elendil eastwardAgannālōDeath-shadowburōdaheavynēnudon-us......zāiralongingnēnudon-usAgannālō burōda nēnud ... zāira nēnudDeath-shadow heavy on-us ... longing on-us......adūnwestizindistraightbatānroadtāidōonceayadda:wentīdōnowkāthaallbatīnaroadslōkhīcrooked... adūn izindi batān tāidō ayadda: īdō kātha batīna lōkhī... west straight road once went now all roads crookedĒphalakfar awayīdōnow (is)YōzāyanLand-of-GiftĒphalak īdō Yōzāyan{far away} {now (is)} Land-of-GiftĒphalfarēphalakfar awayīdōnow (is)hi-AkallabēthShe-that-hath-fallenĒphal ēphalak īdō hi-Akallabēthfar {far away} {now (is)} She-that-hath-fallen