Apostrophes (’) are used in two ways: to show possession and to make contractions. We’ll spend most of this unit working on possession.


An apostrophe is added to a noun to show that the noun owns something. For example, if a girl has her own room, you might refer to it as the girl’s room. Notice that two nouns are involved: girl and room. The apostrophe is added to the noun that possesses (owns) the other.

In the phrase the girl’s room, the letter s is also added to the word girl. But if we were referring to a room shared by two girls, the correct form would be the girls’ room. The apostrophe would be placed after the s. In the latter example, the s is already part of the word because we’re talking about two girls, not one girl. When a plural word already ends in s before it becomes possessive, you add only the apostrophe.

In other words, ask yourself, “Who owns the room?” If the answer is the girl, then you have a word that ends in the letter l, so you add an apostrophe plus -s. But if the answer to the question is the two girls, a word that already ends in -s, then you add only the apostrophe.

Make these into possessive phrases:

1. the voice of the singer = ___________

2. the voices of the four singers = ___________

3. the fleas belonging to one dog = ___________

4. the fleas belonging to twelve dogs = ___________

1. the singer’s voice; 2. the four singers’ voices; 3. one dog’s fleas; 4. twelve dog’s fleas.