In fact, all nouns are divided into those that may be pluralized and those that may not. The latter refer to things as indivisible wholes, whether they be objects, actions, or qualities. They differ from English nouns, however, in two respects. First, Russian nouns also express declension class in their form and some express gender . Not all nouns that end on -a , however, refer to females.
Declension class is an arbitrary class to which all but a handful of nouns belong.
Declension IV nouns usually end on or , but many end on a and some end on e . While natural gender as defined above is not consistent in Russian, grammatical gender is. Grammatical gender is another word for 'agreement', a category reflected in adjectives and verbs that 'agree' with nouns. Agreement in this sense refers to a variable set of endings added to adjectives and past tense verbs to express, not the gender of the adjectives and verbs, but a noun with which they are closely associated. In English, for example, when we say red car , the adjective red is an attribute of car .