Tolkien indicated the Adûnaic language had several verbal moods “represented by auxiliaries” (SD/439): the future, subjunctive and optative. This is similar to English, which can indicate the future with the auxiliary verb “will” (“I will go town”) and the subjunctive with the auxiliary verb “would” (“I would go to town if you came with me”). Unfortunately, Tolkien did not specify what the auxiliaries were, so we must guess from the available evidence.