The apostrophe is used with possessives. Possessives show something belongs to someone or something. In other words, they “possess” something. If we want to show that the present belongs to the girl, it would be stated: The girl’s present.
There are 3 RULES to guide how to make possessives. Rule One To form the possessive of a singular noun, add an apostrophe and s (‘s). Remember a noun is a word that names, a person, place animal or thing. “Singular” means that there is only one. Example: The cat has a brush. The cat’s brush. The lady owns the coat. The lady’s coat.
RULE 2 For a plural nouns ending in s, add only an apostrophe (‘). A plural noun means there is more than one. Since an s was already added to make this noun plural, a second s is not added. Example: The four girls own the notebooks. The four girls’ notebooks. The bones belong to the dogs. The dogs’ bones.
RULE 3 Remember some nouns are made into plurals without adding an s. Irregular plural nouns. For the plural noun that does not end in s, add an apostrophe and s (‘s). Example : The cars belong to the men. The men’s cars. The cheese belongs to the mice. The mice’s cheese. The dishes belong to the women. The women’s dishes.