This document defines and provides examples of the four types of nouns: common nouns, proper nouns, abstract nouns, and collective nouns. It explains that nouns are naming words that identify things, objects, people, places, ideas, and feelings. Common nouns are general names like "cat" or "girl" while proper nouns are specific names that begin with capital letters, like names of people or places. Abstract nouns name intangible concepts like "happiness" or "freedom." Collective nouns identify groups of objects or people like "choir" or "army." The document concludes with examples of nouns used in sentences.