Singular Nouns:
* If the noun ends in "s," add an apostrophe after the "s":
* the dog's bone
* James's car
* If the noun does not end in "s," add an apostrophe and an "s":
* the cat's toy
* the teacher's desk
Plural Nouns:
* If the plural noun ends in "s," add only an apostrophe after the "s":
* the students' books
* the birds' nests
* If the plural noun does not end in "s," add an apostrophe and an "s":
* the children's toys
* the men's hats
Special Cases:
* Pronouns:
* Singular pronouns (he, she, it) take an apostrophe and an "s": his, hers, its
* Plural pronouns (they, we) just add an apostrophe: theirs, ours
* Joint Possession:
* If two or more people own something together, only the last person's name gets an apostrophe:
* John and Mary's house
* Separate Possession:
* If two or more people own separate items, each name gets an apostrophe:
* John's car and Mary's car
Remember:
* The apostrophe indicates possession, not pluralization.
* Use an apostrophe only when showing possession, not for contractions (don't, can't, etc.).
Let me know if you'd like more examples or have any specific possessive words you're unsure about!