The document defines nouns as words that name people, places, animals, or feelings. It explains that nouns can be singular or plural, with plural nouns often formed by adding "s" or changing the spelling. Several rules are provided for making nouns plural depending on if they end in consonants, "y", "o", or other letters. Examples are given to illustrate singular and plural forms. The document concludes with a practice activity asking the reader to identify the correct plural form of sample nouns.