When a noun denotes a human being, it usually falls into v- or y-Classes (1 or 2). Most nouns referring to male entities fall into the v-class, whereas Class 2 contains words related to female entities. Thus "lūlaxuo" (a neighbour) is class 1, but takes v- if a male neighbour and y- if a female. In a few words, changing the prefixes before the nouns indicates grammatical gender; thus: "vоsha" (brother) → "yisha" (sister). Some nouns denoting human beings, however, are not in Classes 1 or 2: "bēr" (child) for example is in class 3.