A great way to remember the possessive apostrophe rules is to remember these three things: For single nouns, add an apostrophe and an 's'. For plural nouns, just add an apostrophe after the 's'. If it's a personal possessive pronoun, it doesn't need an apostrophe at all.

To show possession using an apostrophe, add ’s for individuals (“Smith’s car”) and just the apostrophe after the s for plurals (“the Smiths’ car,” “the Martinezes’ dog”). By convention, names from classical mythology and the Bible ending in s show possession with the apostrophe only (“Jesus’ teachings”).

Here are the rules that will apply: Rule one: If possessive noun is singular, then you need to add apostrophe plus “s”. Rule two: If possessive noun is not ending with the letter “s”, then you always need to add apostrophe plus “s”. Rule three: If possessive noun ends with the “s” and it is plural, what you only need to do is to add apostrophe.

Generally speaking, using an apostrophe to form a possessive noun is pretty simple. If the noun involved is singular, add an apostrophe and an “s” to the end of the word: The lion’s mane (the mane belonging to the lion) The house’s door (the door attached to the house) The lobster’s tank (the tank containing the lobster)