Ad. triconsonantal-verb grammar.
Tolkien states that “the verb form in Adunaic is usually triconsonantal” (SD/416) and there are quite a few examples of triconsonantal verbs, especially compared to the Elvish languages (which have very few verbs derived from triconsonantal roots). There are quite a few attested inflections for these verbs. Based on these forms, my best guess for the conjugations of triconsonantal verbs is as follows:
|aorist||Eliminate the second vowel and add an -a to the verb stem||kalab- → kalba (VT24/12)|
|continuative-present||Change the second vowel to u, add an -i to the verb stem||kalab- → kalubi (SD/251)|
|past||Double the middle consonant, add an -a to the verb stem||kalab- → kallaba (SD/247, 429)|
There isn’t enough information on the continuative past to guess how it might be formed. See the entries for the individual verb tenses for further discussion.
|dubud-||“to fall (under influence/cover of)”|
|kalab-||“to fall (down)”|
|*phazag-||“?to rule, conquer”|
|phurus-||“to gush, flow”|
|rahat-||“to break, rend”|
|*zabath-||“to (be) humble”|
Reference ✧ SD/439 ✧ for example: kalab “fall down”