Blog about English
Using apostrophe-s and of to express possession and relationships.
English expresses possession mainly with the genitive ('s) and the of-construction.
The choice depends on the relationship between the nouns, the type of noun and the style of expression.
Add 's to most singular nouns to express possession.
Examples include the girl's book, John's car and the teacher's desk.
Add only an apostrophe to regular plural nouns ending in -s.
Examples include the students' classroom and my parents' house. Irregular plural nouns take 's.
Irregular plural nouns form the genitive by adding 's.
Examples include the children's toys, the men's room and the women's team.
The of-construction is commonly used with things, abstract nouns and longer noun phrases.
Examples include the roof of the house, the end of the story and the color of the sky.
Use 's mainly with people, animals and certain expressions of time, distance and organizations. Use of mainly with things and abstract relationships.
Both constructions are grammatical in many cases, but one is usually more natural than the other.
The genitive is commonly used with expressions of time.
Examples include a day's work, today's news and two weeks' holiday.
The genitive is used with expressions of distance, value and measurement.
Examples include a mile's walk, a dollar's worth and an hour's drive.
The genitive is frequently used with organizations, countries, cities and other institutions.
Examples include the company's policy, the school's library and the nation's economy.
The position of the apostrophe shows whether possession is shared or separate.
Compare Tom and Mary's house (shared ownership) with Tom's and Mary's houses (separate ownership).
The double genitive combines of with the genitive.
Examples include a friend of John's and a colleague of my father's. It usually refers to one member of a larger group.
The possessed noun may be omitted when it is understood from the context.
Examples include I'm going to Sarah's and This coat is John's.
The genitive may be used with things that are personified.
Examples include the ship's captain, the earth's surface and the company's future.
Some genitives describe the purpose or type of something rather than ownership.
Examples include a children's hospital, a women's magazine and a teachers' conference.
The genitive can follow indefinite pronouns ending in -body or -one.
Examples include somebody else's bag, nobody's fault and everyone's opinion.
Complex noun phrases may contain more than one genitive.
Careful apostrophe placement makes the relationship between nouns clear.
Modern English often prefers the genitive over long of-constructions with animate nouns.
Compare the company's decision with the decision of the company. Both are correct, but the genitive is usually more natural.
Many idiomatic expressions contain the genitive.
Examples include for goodness' sake, at death's door, at arm's length and out of harm's way.
Use apostrophes correctly and choose between 's and of according to standard English usage.
Common mistakes include incorrect apostrophe placement, confusing plural forms with possessive forms and overusing the of-construction where the genitive is more natural.