Earl W. Stevick, Adapting and Writing Language Lessons… (1971)
“ In this cycle, as in Cycle E, the noun suffix /-o/ is employed. Note, however, that this suffix is not used with proper nouns; therefore, it does not suffix to proper names of places. The noun suffix /- (e) n/ as in /ia ohpis-en/ functions to indicate that the speaker does not know, nor has ever known, the location of the object that he is inquiring about. (If a rhetorical question is being posed, or if the speaker once knew the location of the object but has forgotten, the /-o/ suffix is employed; therefore, /ia sidowao/.) ”
