The possessive case shows the relationship of a noun to other words in a sentence. The relationship can be possession, ownership, or another form of association. In general, to form the singular possessive case of a noun, add an apostrophe “s” to the end of the noun. Both common and proper nouns follow the same principle.

The possessive case often conveys possession or ownership, such as Joseph’s book or my opinion. It is the only case in which nouns alter their form (e.g., Joseph to Joseph’s). This simple alteration changes a person, place, or thing into an owner or possessor of something else.

The possessive case of nouns shows ownership or belonging. To form the possessive of a singular noun, add ‘s at the end, like in “dog’s leash” or “girl’s book”. If a singular noun ends in s, you still add ‘s, so “James’s car” is correct.