The GrammarPhile Blog

• my aunt and uncle's house
• Gilbert and Sullivan's musicals
• Minneapolis and St. Paul's transportation system
  but
• my aunt's and uncle's specific talents
• our friends' and neighbors' children

• a cookbook's index
• student assistants' time cards
• my daughter-in-law's office
  but
• the offices of both my daughters-in-law

• an hour's delay
• in three days' time
• six months' leave of absence (or a six-month leave of absence)
• three years' experience

• a consumers' group
• taxpayers' associations
• children's rights
• the women's team
• a boys' club
  but
• Publishers Weekly
• Diners Club
• Department of Veterans Affairs
• a housewares sale

Source: Chicago Manual of Style

We see mistakes often in the use of possessives. That's because there are rules and exceptions. Here are some rules.

A gerund is a present participle used as a noun. The word itself means "to bear" or "to carry on." In English, gerunds end in -ing. Being a noun, a gerund can be used as

• Kansas's legislature
• Chicago's lakefront
• Burns's poems
• Marx's theories
• Berlioz's works
• Strauss's Vienna
• Dickens's novels
• the Lincolns' marriage
• William's reputation
• the Williamses' new house
• Malraux's masterpiece
• Inez's diary
• the Martinezes' daughter
• Josquin des Prez's motets
• dinner at the Browns' (that is, at the Browns' home)
• FDR's legacy
• 1999's heaviest snowstorm
• Yahoo!'s chief executive
  Exceptions (for names of two or more syllables that end in an eez sound):
• Euripides' tragedies
• the Ganges' source
• Xerxes' armies
  and (for words and names ending in unpronounced s)
• Descartes' three dreams
• the marquis' mother
• Francois' efforts to learn English
• Albert Camus' novels (the s is unpronounced)
  but
• Raoul Camus's anthology (the s is pronounced)
  Other exceptions:
• for righteousness' sake
• for goodness' sake
• for Jesus' sake
  but
• Jesus's disciples

Last week, we gave you some general rules on possessives. This week, let's focus on possessives of proper nouns.

Here are some examples of when the letter s is added to a possessive form.

Nouns plural in form, singular in meaning. When the singular form of a noun ending in s looks like a plural and the plural form is the same as the singular, the possessive of both singular and plural is formed by the addition of an apostrophe only. If ambiguity threatens, use of to avoid the possessive.