The document discusses common and proper nouns. It defines common nouns as nouns that name persons, places or things in general and are not capitalized, such as "city" or "newspaper". Proper nouns name specific persons, places or things and are always capitalized, such as "Dallas" or "New York Times". The document then provides examples asking the reader to identify underlined nouns as either common or proper by checking if they are capitalized. It concludes with exercises asking the reader to write sentences correctly capitalizing proper nouns like names and locations.