Possessive nouns are a type of noun that show ownership or a direct connection to something. They are formed by adding an apostrophe and the letter "s" to the end of a singular noun, or just an apostrophe to the end of a plural noun that already ends in "s". For example, "dogs" and "dogs" are possessive nouns. Possessive nouns can be used in two ways in sentences: before another noun, in which case they essentially play the same role as possessive determiners like "my," or as the subject of a sentence. There are four types of possessive nouns: singular possessive nouns, plural possessive nouns, possessive pronouns, and irregular possessive nouns. Some examples of possessive nouns include "the students notes," "Marias car," and "the Empire State Buildings height".