 Most information about Adûnaic grammar comes from an incomplete typescript "Lowdham's Report on the Adûnaic Language", written by Tolkien to accompany "The Notion Club Papers".The report discusses phonology and morphological processes in some detail, and starts to discuss nouns, but breaks off before saying much about verbs, other parts of speech or the grammar as a whole.It appears that Tolkien abandoned work on the language after writing this portion of the Report, and never returned to it.