Usage
1. Use an apostrophe to make contractions; the apostrophe takes the place of missing letters:
- You can’t go in while the interview is taking place.
- He’ll be right back.
- I would’ve submitted an entry if I’d had time.
Keeping in mind that the apostrophe means missing letters, you can remember that “it’s” means “it is,” but “its” is the possessive (belonging to “it”).
2. Use an apostrophe to show possession, that one person or thing owns something or has a particular quality:
- Denise’s senior thesis topic is one that no one else is writing about.
- Michael’s curiosity gets him into trouble sometimes.
If a person’s name ends in “s,” pronunciation can guide you somewhat:
- Chris’s dog chewed up Lois’s socks but left alone her copy of Sophocles’ plays.
To make a plural word that ends in “s” possessive, simply add an apostrophe:
- The students’ projects were nowhere near being done.
- The Simpsons’ next-door neighbor is Ned Flanders.
Remember that some plural words don’t end in “s”; in those cases, add an apostrophe and “s” to make a possessive:
- The children’s coats were on the floor.
When a word that already ends in “s” is both plural and possessive, add an “es” to make the word plural and an apostrophe to make the word possessive:
- The school buses’ schedules were on a delay because of the snow.
- The Flanderses’ next-door neighbor is Homer Simpson.
** Note: Though “Flanderses” is technically correct for the plural of “Flanders,” it may be less awkward to say “The Flanders family”
3. Rarely use an apostrophe to make plurals, except in cases such as letters or numbers:
- I got straight 4.0’s last semester.
- How many Q’s are there in a Scrabble game?
However, this rule is flexible: How many Qs are there in a Scrabble game?
Most conventions omit the apostrophe when speaking of plural years, such as a decade:
- The 1980s were a terrible decade for fashion but the ‘90s were better.