The possessive case is a grammatical case that indicates ownership or possession of a noun or pronoun by another noun or pronoun. This can apply both to proper nouns, such as individuals or geographic locations called by name, or to common nouns such as cars, houses, or dogs. Nearly every language has a possessive case, though the structure of creating this case varies widely. It is one of the most commonly used genitive cases, which are the linguistic cases that indicate the relationship between two nouns.
In English, the possessive case is usually expressed in one of two ways. When the possessing noun comes first in a phrase, an apostrophe and the letter "s" are generally added to the word. For example, a bike owned by Sally would be described as "Sally's bike." In the case of a plural word, only an apostrophe is added to the end. For example, a building owned by a business would be described as the "business' building."
Some English pronouns also can be used as possessives in and of themselves. For example, in the sentence "Did you see her?" the pronoun "her" indicates a female. If, however, the sentence were to read "that is her bike," the word "her" would indicate possession by the female.
When an English pronoun follows the noun it possesses, it usually will not require an apostrophe, but merely an "s." For example, "her" becomes "hers" and "their" becomes "theirs." In a sentence, an example would be: "the bike is hers."
Possession can also be indicated by placing the possessed noun first, the possessing noun second and inserting the word "of" in between the two. For example, "the bike of Sally." This construction is generally considered awkward in English and is most often exchanged for the simpler apostrophe-s combination. This preference is not common around the world, however.
In many other languages, including most of the romance languages, the longer construction is actually the more commonly used form of the possessive case. For example, "the girl's bike" would translate to "la bicyclette de la fille" in French. This literally reads "the bicycle of the girl." In Spanish, the phrase would become "la moto de la muchacha," which also literally translates to "the bike of the girl." For this reason, the possessive case can be a challenge both for native English speakers attempting to learn foreign languages and for non-native speakers attempting to learn English.
