The likely primitive form of the Classical Adûnaic plural inflection 
-î- (SD/429), appearing in a few examples of primitive plurals in the form 
-yi: 
manaw+yi, 
izray+yi (SD/424). Tolkien gave no indication of whether the primitive inflection was also used as an infix, as was the case for Classical
            Adûnaic plurals of 
strong-nouns.