English
Guidelines for Forming Possessive Nouns

• Add ‘s to most singular nouns; eg., the student’s computer (ownership), Canada’s citizens (origin), Robertson’s writing (authorship), one year’s time (measurement).
• Add ’ to nouns ending in an s sound; eg., the students’ computers, the countries’ citizens, the Robertsons’ writings (more than one Robertson), three years’ time.
• Animate versus inanimate nouns: As a matter of style, some careful writers prefer to reserve the apostrophe construction for people and animals; eg., roof of the car or the car roof (better than the car’s roof); colour of the boat or the boat colour (better than the boat’s colour).
• Descriptive versus possessive nouns: When nouns are used as adjectives to provide description or identification only, the possessive form is not used; eg., Claims Department, not Claims’ Department.
• Make compound words possessive by adding an apostrophe or an ’s to the final element of the compound; eg., his mother-in-law’s property, notary public’s seal, onlookers’ interest.
• Incomplete Possessives: When the second noun in a possessive noun construction is unstated, the first noun is treated as a possessive; eg., We will meet at Sarah’s [home] after the concert; this year’s games are better than last year’s [games]; Sam will meet us at the stationer’s [store].
• Separate or combined ownership: When two nouns express separate ownership, make both possessive. When two nouns express combined ownership, make only the second one possessive; eg., John’s and May’s cars, the husband and wife’s home.
• Names of organizations: Organizations with possessives may or may not use apostrophes. Follow the style of the individual organization; eg., Tony’s Restaurants, Sears, Metro Tenants Association.
• Abbreviations: Make abbreviations possessive by following the same guidelines as for animate nouns; eg., CBC’s coverage, the Ph.D.’s credentials, Envirotech Inc.’s products.
• Possessive singular proper nouns that end in s sounds may be created in two ways: by adding either ’s or ’; eg.,the book belonging to Mrs. Ross is either Mrs. Ross’s book (traditional style) or Mrs. Ross’ book (popular style).
• Plural proper nouns are always made possessive with the addition of ’ only; eg., the Rosses’ books.