This document defines and categorizes nouns. It discusses the different kinds of nouns including proper, common, mass/noncount, count, abstract, concrete, collective, and compound nouns. It also describes noun forms including singular/plural regular and irregular forms, gender, cases, and possessive forms. Key points covered are the different functions of nouns as subjects, objects, in possessive constructions. Verbal nouns ending in "-ing" and their functions are also defined.