The meaning of the noun is thingness.
According to the type of nomination they may be proper and common.
According to the form of existence they may be animate and inanimate. Animate nouns in their turn fall into human and non-human.
According to their quantitative structure nouns can be countable, uncountable and collective.
Morphologically nouns are characterized by the grammatical categories of number (singular, plural) and case (common, genitive притяжательный – limited case theory). Some scholars admit the existence of the category of gender (eng. Human animate nouns can be of 2 genders: feminine and masculine; all the rest are classified as nouns of neuter gender) and the category of article determination (the definite, the indefinite, the zero)
The primary substantive functions of the noun are those of the subject and the object. The noun can be used in the sentence in all syntactic functions but predicate.