From Tolkien’s notes (SD/439) we know there are four Adûnaic verb tenses: the aorist, past, continuative present and continuative past tenses. Unfortunately, these notes provide no information on how those tenses are conjugated. We have to guess which of the attested verb forms belong to each tense. To make matters worse, the aorist tense can function as the past tense in narratives, while the ordinary past can function as a pluperfect (SD/439). This means that English glosses are not a reliable guide for determining Adûnaic verb tenses.

To analyze Adûnaic verbs, most authors (VSH/27-29, AL/Adûnaic, LGtAG) have noted two common patterns to Adûnaic verb conjugations after you remove the pronominal prefixes and the plural suffix -m:

• Syncopated forms: Forms with vowel-loss, only attested for triconsonantal verbs: kalba, dubda.
• Geminate forms: Forms with double-consonants, attested for both tri- and biconsonantal verbs: kallaba, yadda. There is a third geminate form of a derived verb: azaggara.

The general assumption is that similar verb forms belong to the same tense, but there is no general consensus in the literature as to which patterns belong to each tense, or even which examples fall under each pattern. The following entries discuss my best guesses for how Adûnaic verbs are conjugated, with additional notes on the alternate theories of other authors.